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Solid Type Country/Origin
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Myanmar (Burma), Mogok

Record No:    52

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Atikarnsakul, U., Vertriest, W. et al. (2018) Characterization of blue sapphires from the Mogok Stone Tract, Mandalay region, Burma (Myanmar). Gemological Institute of America, Bangkok, June, 56 pp.; RWHL* see pp. 15, 18, 20, 53, 55
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Sri Lanka (Ceylon),

Record No:    53

Geology:    Alluvial gravels derived from source rocks formed via granulite facies metamorphism. It is thought that intrusions of basic charnockites of basaltic chemistry into the Al-rich sediments caused their desilication, resulting in the formation of corundum

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Sahama, T.G., Lehtinen, M. et  al. (1973) Natural boehmite single crystals from Ceylon. Contributions to Mineralogy and Petrology, Vol. 39, pp. 171–174; RWHL see pp. 172
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
United States, Missouri River

Record No:    54

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Common

References:
  • Zwaan, J.C., Buter, E. et al. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry, and indications of a metamorphic origin. Gems & Gemology, Vol. 51, No. 4, Winter, pp. 370–391; RWHL* see pp. 379
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Vietnam, Yen Bai

Record No:    55

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 193
Brookite - Orthorhombic
Solid Type:  Solid–Primary
  • Brookite Orthorhombic TiO₂
    Notes:
    Polymorphs:Akaogiite, Anatase, Riesite, Rutile, UM1991-08-O:Ti, UM2000-41-O:Ti
Myanmar (Burma), Mogok

Record No:    56

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Rare

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 341
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Afghanistan, Jegdalek

Record No:    57

Geology:    Ruby in situ in metamorphosed dolomitic limestone cut by granitic intrusions of Oligocene age

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Common

References:
  • Beesley, C.R. (1986) Pakistan’s emeralds: A trickle becomes a stream. Jewelers’ Circular-Keystone, February, pp. 359–365; RWHL see pp.
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Afghanistan, Jegdalek

Record No:    58

Geology:    Ruby in situ in metamorphosed dolomitic limestone cut by granitic intrusions of Oligocene age

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Bowersox, G.W. (1985) A status report on gemstones from Afghanistan. Gems & Gemology, Vol. 21, No. 4, Winter, pp. 192–204; RWHL* see pp. 202
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
India, Sumjam

Record No:    59

Geology:    Sapphire in situ and in secondary deposits derived from a pegmatite associated with actinolite-tremolite lenses

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 198
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Madagascar, Andranondambo

Record No:    60

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Kiefert, L., Schmetzer, K. et al. (1996) Sapphires from Andranondambo area, Madagascar. Journal of Gemmology, Vol. 25, No. 3, pp. 185–209; RWHL* see pp. 90
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Myanmar (Burma), Mogok

Record No:    61

Geology:    Ruby occurs in contact or regionally metamorphosed limestones cut by clay bands

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 61, 117
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Pakistan, Hunza

Record No:    62

Geology:    Ruby and sapphire in situ in calcitic or dolomitic marble

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1982) Gemstones of Pakistan: Emerald, ruby and spinel. Gems & Gemology, Vol. 18, No. 3, Fall, pp. 123–129; RWHL* see pp. 136–137
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Sri Lanka (Ceylon),

Record No:    63

Geology:    Alluvial gravels derived from source rocks formed via granulite facies metamorphism. It is thought that intrusions of basic charnockites of basaltic chemistry into the Al-rich sediments caused their desilication, resulting in the formation of corundum

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. (1940) Characteristics of Ceylon rubies. Gems & Gemology, Vol. 1, No. 8, pp. 121–124; RWHL see pp. 124
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Tajikistan, Snezhny

Record No:    64

Geology:    Ruby found in mineralized zone of marbles

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Common

References:
  • Smith, C.P. (1998) Rubies and pink sapphires from the Pamir Range in Tajikistan, former USSR. Journal of Gemmology, Vol. 26, No. 2, pp. 103–109; RWHL see pp. 104, 107
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Tanzania, Tunduru

Record No:    65

Geology:    Ruby and sapphire in secondary deposits of unknown origin

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Common

References:
  • Chitty, W. (2009) A Study of Sapphires and Rubies from Tanzania’s Tunduru District. Kingston University, London, BSc Thesis in Gemology and Applied Mineralogy, 32 pp.; RWHL* see pp. 16–17, 24
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Tanzania, Umba

Record No:    67

Geology:    Ruby and sapphire in situ in desilicated pegmatites cutting a serpentinite pipe and from alluvials derived from that pipe

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Hänni, H.A. (1987) On corundums from Umba Valley, Tanzania. Journal of Gemmology, Vol. 20, No. 5, January, pp. 278–284; RWHL* see pp. 283
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
United States, Dry Cottonwood Creek, Missouri River, Yogo, MT

Record No:    68

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 346
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Vietnam, Yen Bai

Record No:    69

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Common

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 193
Calcite Group - Trigonal
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    70

Geology:    Ruby in an amphibole-rich rock

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8
Carbon - Amorphous
Solid Type:  Solid–Primary
  • Carbon - C
United States, Dry Cottonwood Creek, MT

Record No:    71

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Rare

References:
  • Zwaan, J.C., Buter, E. et al. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry, and indications of a metamorphic origin. Gems & Gemology, Vol. 51, No. 4, Winter, pp. 370–391; RWHL* see pp. 379
Catapleiite - Monoclinic
Solid Type:  Solid–Primary
  • Catapleiite Monoclinic Na₂Zr(Si₃O₉) · 2H₂O
    Notes:
    Polymorphs:Gaidonnayite
Greenland, Aappaluttoq

Record No:    72

Geology:    Ruby in amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8
Chalcopyrite Group - Tetragonal
Solid Type:  Solid–Primary
Mozambique, Montepuez

Record No:    73

Geology:    Primary and secondary ruby associated with amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Pardieu, V., Sangsawong, S. et al. (2013) Rubies from the Montepuez area (Mozambique). Gemological Institute of America, October 5, 84 pp.; RWHL* see pp. 31–32, 42, 50, 73–76
Chlorite Group - Mostly Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - A₅₋₆T₄Z₁₈
    Notes:A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH
    Polymorphs:
Greenland, Aappaluttoq

Record No:    74

Geology:    Ruby in amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8, 11
Chlorite Group - Mostly Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - A₅₋₆T₄Z₁₈
    Notes:A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH
    Polymorphs:
Myanmar (Burma), Mong Hsu

Record No:    75

Geology:    Ruby occurs in situ in marbles and alluvial deposits derived from the same

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Peretti, A., Schmetzer, K. et al. (1995) Rubies from Mong Hsu. Gems & Gemology, Vol. 31, No. 1, Spring, pp. 2–26; RWHL* see pp. 16, 18
Chlorite Group - Mostly Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - A₅₋₆T₄Z₁₈
    Notes:A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH
    Polymorphs:
Pakistan, Hunza

Record No:    76

Geology:    Ruby and sapphire in situ in calcitic or dolomitic marble

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Gübelin, E.J. (1982) Gemstones of Pakistan: Emerald, ruby and spinel. Gems & Gemology, Vol. 18, No. 3, Fall, pp. 123–129; RWHL* see pp. 137
Chlorite Group - Mostly Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - A₅₋₆T₄Z₁₈
    Notes:A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH
    Polymorphs:
Rwanda, Cyangugu

Record No:    77

Geology:    Sapphire in deposits associated with alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Krzemnicki, M.S., Hänni, H.A. et al. (1996) Investigations on sapphires from an alkali basalt, South West Rwanda. Journal of Gemmology, Vol. 25, No. 2, pp. 90–106; RWHL* see pp. 99
Chlorite Group - Mostly Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - A₅₋₆T₄Z₁₈
    Notes:A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH
    Polymorphs:
Vietnam, Yen Bai

Record No:    78

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 190, 193
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    79

Geology:    Sapphires found in eluvial and alluvial gravels derived from alkali basalts and pyroclastics

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Coenraads, R.R. (1992a) Sapphires and rubies associated with volcanic provinces: Inclusions and surface features shed light on their origin. Australian Gemmologist, Vol. 18, No. 3, pp. 70–78; RWHL* see pp. 71
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Cambodia, Pailin

Record No:    80

Geology:    Sapphires and rubies found in alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Saeseaw, S., Sangsawong, S. et al. (2017b) An In-Depth Study of Blue Sapphires from Pailin, Cambodia. Gemological Institute of America, Bangkok, 22 December, 45 pp.; RWHL see pp. 15, 22, 24
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
China, Fujian, Hainan, Shandong

Record No:    81

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Guo, J., O’Reilly, S.Y. et al. (1996) Corundum from basaltic terrains: A mineral inclusion approach to the enigma. Contributions to Mineralogy and Petrology, Vol. 122, pp. 368–386; RWHL* see pp. 371–372
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Thailand (Siam), Bo Welu, Chanthaburi-Trat

Record No:    82

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Promwongnan, S. and Sutthirat, C. (2019) Mineral inclusions in ruby and sapphire from the Bo Welu gem deposit in Chanthaburi, Thailand. Gems & Gemology, Vol. 55, No. 3, Fall, pp. 354–369; RWHL* see pp. 357, 364–367
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Madagascar, Andapa, Antsiranana

Record No:    83

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 58–59
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Nigeria, Mambilla

Record No:    84

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Common

References:
  • Pardieu, V., Sangsawong, S. et al. (2014) Blue sapphires from the Mambilla Plateau, Taraba State, Nigeria. Gemological Institute of America, 16 August, 47 pp.; RWHL* see pp. 31, 36
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Thailand (Siam), Bo Ploi, Kanchanaburi

Record No:    85

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 58–59
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Vietnam, Dak Lak

Record No:    86

Geology:    Rubies/sapphires found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 58–59
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Laos, Huay Xai

Record No:    87

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 58–59
Cordierite - Orthorhombic
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    88

Geology:    Ruby in amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8, 10
Cordierite - Orthorhombic
Solid Type:  Solid–Primary
Vietnam, Dak Nong province

Record No:    89

Geology:    Sapphires found in alluvial gravels derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Rare

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 57–58
Cosalite - Orthorhombic
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    90

Geology:    Ruby in amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8
Cristobalite - Tetragonal
Solid Type:  Solid–Primary
  • Cristobalite Tetragonal SiO₂
    Notes:
    Polymorphs:Coesite, Keatite, Mogánite, Quartz, Seifertite, Stishovite, Tridymite
USA (Montana), Rock Creek, Mt

Record No:    91

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Rare

References:
  • Zwaan, J.C., Buter, E. et al. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry, and indications of a metamorphic origin. Gems & Gemology, Vol. 51, No. 4, Winter, pp. 370–391; RWHL* see pp. 379, 384
Dawsonite - Orthorhombic
Solid Type:  Solid–Primary
Myanmar (Burma), Mong Hsu

Record No:    92

Geology:    Ruby occurs in situ in marbles and alluvial deposits derived from the same

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Rare

References:
  • Giuliani, G., Dubessy, J. et al. (2018) Fluid inclusion study of trapiche and non-trapiche rubies from the Mong Hsu district, Myanmar. Canadian Mineralogist, Vol. 56, No. 5, pp. 691–703; RWHL see pp. 696–698, 700, 702
Diaspore Group - Orthorhombic
Solid Type:  Solid–Primary
  • Diaspore Orthorhombic AlO(OH)
    Notes:
    Polymorphs:Böhmite
Madagascar, Marosely

Record No:    94

Geology:    Ruby & sapphire in alluvial deposits of metamorphic origin

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Cartier, L. (2009) Ruby and sapphire from Marosely, Madagascar. Journal of Gemmology, Vol. 31, No. 5–8, pp. 171–179; RWHL see pp. 172, 174–175, 178
Diaspore Group - Orthorhombic
Solid Type:  Solid–Primary
  • Diaspore Orthorhombic AlO(OH)
    Notes:
    Polymorphs:Böhmite
Myanmar (Burma), Mong Hsu

Record No:    95

Geology:    Ruby occurs in situ in marbles and alluvial deposits derived from the same

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Common

References:
  • Smith, C.P. (1995) A contribution to understanding the infrared spectra of rubies from Mong Hsu, Myanmar. Journal of Gemmology, Vol. 24, No. 5, Jan., pp. 321–335; RWHL* see pp. 321, 323–324, 329–330
Diaspore Group - Orthorhombic
Solid Type:  Solid–Primary
  • Diaspore Orthorhombic AlO(OH)
    Notes:
    Polymorphs:Böhmite
Myanmar (Burma), Mogok

Record No:    96

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Atikarnsakul, U., Vertriest, W. et al. (2018) Characterization of blue sapphires from the Mogok Stone Tract, Mandalay region, Burma (Myanmar). Gemological Institute of America, Bangkok, June, 56 pp.; RWHL* see pp. 36, 39
Diaspore Group - Orthorhombic
Solid Type:  Solid-Secondary
  • Diaspore Orthorhombic AlO(OH)
    Notes:
    Polymorphs:Böhmite
Sri Lanka (Ceylon),

Record No:    97

Geology:    Alluvial gravels derived from source rocks formed via granulite facies metamorphism. It is thought that intrusions of basic charnockites of basaltic chemistry into the Al-rich sediments caused their desilication, resulting in the formation of corundum

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. and Koivula, J.I. (2005) Photoatlas of Inclusions in Gemstones, Volume 2. Basel, Switzerland, Opinio Publishers, 830 pp.; RWHL* see pp. 209, 236
Diaspore Group - Orthorhombic
Solid Type:  Solid–Primary
  • Goethite Orthorhombic α-Fe³⁺O(OH)
    Notes:
    Polymorphs:Feroxyhyte, Lepidocrocite, UM1985-08-OH:Fe
Myanmar (Burma), Mogok

Record No:    98

Geology:    Alluvial gravels derived from source rocks formed via granulite facies metamorphism. It is thought that intrusions of basic charnockites of basaltic chemistry into the Al-rich sediments caused their desilication, resulting in the formation of corundum

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Soonthorntanikul, W., Vertriest, W. et al. (2017) An in-depth gemological study of blue sapphires from the Baw Mar mine (Mogok, Myanmar). GIA News from Research, February, 87 pp.; RWHL* see pp. 10, 36, 45
Diaspore Group - Orthorhombic
Solid Type:  Solid–Primary
  • Goethite Orthorhombic α-Fe³⁺O(OH)
    Notes:
    Polymorphs:Feroxyhyte, Lepidocrocite, UM1985-08-OH:Fe
Vietnam, Dak Nong province

Record No:    101

Geology:    Sapphires found in alluvial gravels derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Occasional

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 48–50
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Afghanistan, Jegdalek

Record No:    102

Geology:    Ruby in situ in metamorphosed dolomitic limestone cut by granitic intrusions of Oligocene age

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Brückl, K. (1937) Die Minerallagerstätten von Östafghanistan. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, B-Bd 72, Abt. A, H 1, pp. 1–97; RWHL* see pp.
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    103

Geology:    Ruby in an amphibole-rich rock (tschermakitic)

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Madagascar, Andranondambo

Record No:    104

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Occasional

References:
  • Milisenda, C. and Henn, U. (1996) Compositional characteristics of sapphire from a new find in Madagascar. Journal of Gemmology, Vol. 25, No. 3, pp. 177–184; RWHL see pp. 182
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    105

Geology:    Ruby occurs in contact or regionally metamorphosed limestones cut by clay bands

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 325–326
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Myanmar (Burma), Mong Hsu

Record No:    106

Geology:    Ruby occurs in situ in marbles and alluvial deposits

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Occasional

References:
  • Smith, C.P. and Surdez, N. (1994) The Mong Hsu ruby: A new type of Burmese ruby. JewelSiam, Vol. 4, No. 6, Dec–Jan, pp. 82–98; RWHL see pp.
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Pakistan, Hunza

Record No:    107

Geology:    Ruby and sapphire in situ in calcitic or dolomitic marble

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1982) Gemstones of Pakistan: Emerald, ruby and spinel. Gems & Gemology, Vol. 18, No. 3, Fall, pp. 123–129; RWHL* see pp. 136
Dolomite Group - Trigonal
Solid Type:  Solid–Primary
Vietnam, Yen Bai

Record No:    108

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 193
Euxenite Group - Orthorhombic
Solid Type:  Solid–Primary
  • Fersmite Orthorhombic (Ca,Ce,Na)(Nb,Ta,Ti)₂(O,OH,F)₆
China, Mingxi, Fujian

Record No:    110

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Guo, J., O’Reilly, S.Y. et al. (1996) Corundum from basaltic terrains: A mineral inclusion approach to the enigma. Contributions to Mineralogy and Petrology, Vol. 122, pp. 368–386; RWHL* see pp. 371–372, 379
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Australia,

Record No:    111

Geology:    Sapphires found in eluvial and alluvial gravels derived from alkali basalts and pyroclastics

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1969) On the nature of mineral inclusions in gemstones. Journal of Gemmology, Vol. 11, No. 5, Jan., pp. 149–192; RWHL* see pp. 173–174
Feldspar Group - Orthorhomic, Monoclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Brazil,

Record No:    112

Geology:    Sapphires found in alluvial deposits of unknown origin

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 51–53
Feldspar Group - Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Cambodia, Pailin

Record No:    113

Geology:    Sapphires and rubies found in alluvial gravels derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 135
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
China, Fujian, Jiangsu, Shandong

Record No:    114

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Guo, J., O’Reilly, S.Y. et al. (1996) Corundum from basaltic terrains: A mineral inclusion approach to the enigma. Contributions to Mineralogy and Petrology, Vol. 122, pp. 368–386; RWHL* see pp. 369, 371–375
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Colombia, Mercaderes–Río Mayo

Record No:    115

Geology:    Secondary deposits derived from an unidentified source rock

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Occasional

References:
  • Duroc-Danner, J.M. (2002) A Study of Colombian Corundum. Université de Nantes, Nantes, Diplôme d’Université de Gemmologie, 217 pp.; RWHL* see pp. 35, 53, 59–60, 72
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Greenland, Aappaluttoq

Record No:    116

Geology:    Ruby in an amphibole-rich rock (tschermakitic)

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Thirangoon, K. (2009) Ruby and Pink Sapphire from Aappaluttoq, Greenland: Status of on-going research. Gemological Institute of America, March, 18 pp.; RWHL see pp. 8
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
India (Kashmir), Sumjam

Record No:    117

Geology:    Sapphire in situ and in secondary deposits derived from a pegmatite associated with actinolite-tremolite lenses

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Hänni, H.A. (1990) A contribution to the distinguishing characteristics of sapphire from Kashmir. Journal of Gemmology, Vol.  22, No.  2, pp. 67–75; RWHL* see pp. 73–74
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Laos, Huay Xai

Record No:    118

Geology:    Sapphires found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 51–53
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Madagascar, Andranondambo

Record No:    119

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 251
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Malawi, Chimwadzulu Hill

Record No:    121

Geology:    Corundums in situ in an epidotized amphibolite, embedded in a coarse aggregate of hornblende crystals, which is itself enclosed in a fine-grained granular matrix of epidote and plagioclase

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Henn, U. and Bank, H. (1990) Blaue saphire aus Malawi. Zeitschrift der Deutschen Gemmologischen Gesellschaft, Vol. 39, No. 1, pp. 89–92; RWHL see pp.
Feldspar Group - Triclinic or Triclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    122

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1969) On the nature of mineral inclusions in gemstones. Journal of Gemmology, Vol. 11, No. 5, Jan., pp. 149–192; RWHL* see pp. 174
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mong Hsu

Record No:    123

Geology:    Ruby occurs in situ in marbles and alluvial deposits derived from the same

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Rare

References:
  • Peretti, A., Mullis, J. et al. (1996) The role of fluorine in the formation of colour zoning in rubies from Mong Hsu, Myanmar (Burma). Journal of Gemmology, Vol. 25, No. 1, pp. 3–19; RWHL* see pp. 12
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Nigeria, Jos, Kaduna Province

Record No:    124

Geology:    Sapphire in alluvial and residual deposits from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Kiefert, L. and Schmetzer, K. (1987) Blue and yellow sapphire from Kaduna Province, Nigeria. Journal of Gemmology, Vol. 20, No. 7/8, pp. 427–442; RWHL* see pp. 440
Feldspar Group - Monoclinic or Triclinic
Solid Type:  Solid–Primary
  • Orthoclase Monoclinic K(AlSi₃O₈)
    Notes:
    Polymorphs:Kokchetavite, Microcline, Sanidine
Russia, Nezametnoye, Primorye region, Far East Russia

Record No:    125

Geology:    Sapphire found in alluvial placers of unknown origin.

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL* see pp. 51–53
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Microcline Triclinic K(AlSi₃O₈)
    Notes:
    Polymorphs:Kokchetavite, Orthoclase, Sanidine
Tajikistan, Snezhny

Record No:    126

Geology:    Ruby found in mineralized zone of marbles

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Sorokina, E.S., Litvinenko, A.K. et al. (2015) Rubies and Sapphires from Snezhnoe, Tajikistan. Gems & Gemology, Vol. 51, No. 2, pp. 160–175; RWHL* see pp. 167, 170–171, 174
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Tajikistan, Snezhny

Record No:    127

Geology:    Ruby found in mineralized zone of marbles

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Sorokina, E.S., Litvinenko, A.K. et al. (2015) Rubies and Sapphires from Snezhnoe, Tajikistan. Gems & Gemology, Vol. 51, No. 2, pp. 160–175; RWHL* see pp. 167, 170–171, 174
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Tanzania, Tunduru

Record No:    128

Geology:    Ruby and sapphire of various colors of unknown geologic origin

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Occasional

References:
  • Chitty, W. (2009) A Study of Sapphires and Rubies from Tanzania’s Tunduru District. Kingston University, London, BSc Thesis in Gemology and Applied Mineralogy, 32 pp.; RWHL* see pp. 20–21
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Tanzania, Umba

Record No:    129

Geology:    Ruby and sapphire in situ in desilicated pegmatites cutting a serpentinite pipe and from alluvials derived from that pipe

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 129
Feldspar Group - Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Thailand/Cambodia, Chanthaburi/Trat/Pailin

Record No:    130

Geology:    Sapphires and rubies found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. (1971) New analytical results of the inclusions in Siam rubies. Journal of Gemmology, Vol. 12, No.  7, July, pp.  242–252; RWHL* see pp. 248
Feldspar Group - Orthorhomic, Monoclinic or Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Silicates
Thailand (Siam), Bo Ploi

Record No:    131

Geology:    Sapphires found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Gunawardene, M. and Chawla, S.S. (1984) Sapphires from Kanchanaburi Province, Thailand. Journal of Gemmology, Vol. 19, No. 3, pp. 228–239; RWHL see pp. 235–236
Feldspar Group - Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Thailand (Siam), Chanthaburi

Record No:    132

Geology:    Sapphires found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Saeseaw, S., Sangsawong, S. et al. (2017) A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics. Gemological Institute of America, Bangkok, 12 April, 42 pp.; RWHL see pp. 16, 21–23
Feldspar Group - Triclinic or Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Thailand (Siam), Bo Welu, Chanthaburi

Record No:    133

Geology:    Ruby & sapphire found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Promwongnan, S. and Sutthirat, C. (2019) Mineral inclusions in ruby and sapphire from the Bo Welu gem deposit in Chanthaburi, Thailand. Gems & Gemology, Vol. 55, No. 3, Fall, pp. 354–369; RWHL* see pp. 357, 359–367
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
USA (Montana), Dry Cottonwood, Rock Creek

Record No:    134

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Unknown

References:
  • Zwaan, J.C., Buter, E. et al. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry, and indications of a metamorphic origin. Gems & Gemology, Vol. 51, No. 4, Winter, pp. 370–391; RWHL* see pp. 376, 379–380
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Vietnam, Yen Bai

Record No:    135

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 193
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
  • Not Specified - Na(AlSi₃O₈) to Ca(Al₂Si₂O₈)
Vietnam, Quy Chau, Dak Nong, Dak Lap

Record No:    136

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Diep, P.T.M. (2015) Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals. Mainz University doctorate thesis; 140 pp.; RWHL*. see pp. 51–53
Feldspathoid Group - Hexagonal
Solid Type:  Solid–Primary
  • Nepheline Hexagonal Na₃K(Al₄Si₄O₁₆)
    Notes:
    Polymorphs:Trinepheline
Myanmar (Burma), Mogok

Record No:    137

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Atikarnsakul, U., Vertriest, W. et al. (2018) Characterization of blue sapphires from the Mogok Stone Tract, Mandalay region, Burma (Myanmar). Gemological Institute of America, Bangkok, June, 56 pp.; RWHL* see pp. 7
Feldspathoid Group - Hexagonal
Solid Type:  Solid–Primary
  • Nepheline Hexagonal Na₃K(Al₄Si₄O₁₆)
    Notes:
    Polymorphs:Trinepheline
Thailand (Siam), Bo Ploi, Kanchanaburi

Record No:    138

Geology:    Sapphires and rubies found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Saminpanya, S. and Sutherland, F.L. (2011) Different origins of Thai area sapphire and ruby, derived from mineral inclusions and co-existing minerals. European Journal of Mineralogy, Vol. 23, No. 4, Aug.–Sept., pp. 683–694; RWHL* see pp.
Feldspathoid Group - Hexagonal
Solid Type:  Solid–Primary
  • Nepheline Hexagonal Na₃K(Al₄Si₄O₁₆)
    Notes:
    Polymorphs:Trinepheline
Thailand, Bo Welu, Chanthaburi

Record No:    139

Geology:    Sapphires and rubies found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Promwongnan, S. and Sutthirat, C. (2019b) Mineral inclusions in ruby and sapphire from the Bo Welu gem deposit in Chanthaburi, Thailand. Gems & Gemology, Vol. 55, No. 3, Fall, pp. 354–369; RWHL see pp.
Feldspathoid Group - Hexagonal
Solid Type:  Solid–Primary
  • Nepheline Hexagonal Na₃K(Al₄Si₄O₁₆)
    Notes:
    Polymorphs:Trinepheline
Vietnam, Yen Bai

Record No:    140

Geology:    Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Khoi, N.N., Sutthirat, C. et al. (2011) Ruby and sapphire from the Tan Huong-Truc Lau area, Yen Bai province, northern Vietnam. Gems & Gemology, Vol. 47, No. 3, Fall, pp. 182–195; RWHL* see pp. 193
Fergusonite-(Y) - Tetragonal
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    141

Geology:    Ruby occurs in contact or regionally metamorphosed limestones cut by clay bands

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 127
Fluorite Group - Isometric
Solid Type:  Solid–Primary
Madagascar, Andranondambo

Record No:    142

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 251
Fluorite Group - Isometric
Solid Type:  Solid–Primary
Myanmar (Burma), Mong Hsu

Record No:    143

Geology:    Ruby occurs in situ in marbles and alluvial deposits derived from the same

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Rare

References:
  • Peretti, A., Schmetzer, K. et al. (1995) Rubies from Mong Hsu. Gems & Gemology, Vol. 31, No. 1, Spring, pp. 2–26; RWHL*. see pp.
Fluorite Group - Isometric
Solid Type:  Solid–Primary
Tanzania, Tunduru

Record No:    144

Geology:    Ruby and sapphire in secondary deposits of unknown origin

Origin Confidence:    2: Obtained in a market near the mines

Frequency Seen:    Unknown

References:
  • Chitty, W. (2009) A Study of Sapphires and Rubies from Tanzania’s Tunduru District. Kingston University, London, BSc Thesis in Gemology and Applied Mineralogy, 32 pp.; RWHL see pp. 24–25
Garnet Group - Isometric
Solid Type:  Solid–Primary
USA (Montana), Dry Cottonwood, Missouri River, Rock Creek, Yogo

Record No:    145

Geology:    Sapphire in situ and from alluvials derived from a lamprophyric rock intruded into limestone (Yogo); sapphire in alluvials believed derived from igneous dikes of unknown composition (non-Yogo)

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 227–228
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Pyrope Isometric Mg₃Al₂(SiO₄)₃
Tanzania, Morogoro

Record No:    146

Geology:    Ruby as alluvial deposits or as lenses in calc-silicate rocks within marbles

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Hänni, H.A. and Schmetzer, K. (1991) New rubies from the Morogoro area, Tanza­nia. Gems & Gemology, Vol. 27, No. 3, pp. 156–167; RWHL* see pp.
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Pyrope Isometric Mg₃Al₂(SiO₄)₃
Thailand, Bo Rai, Bo Welu, Chanthaburi/Trat

Record No:    147

Geology:    Sapphires and rubies found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Promwongnan, S. and Sutthirat, C. (2019) An update on mineral inclusions and their composition in ruby from the Bo Rai gem field in Trat Province, eastern Thailand. Journal of Gemmology, Vol. 36, No. 7, pp. 634–645; RWHL* see pp. 635, 640–641, 643
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Not Specified - X₃Z₂(SiO₄)₃
    Notes:X = Mg, Ca, Fe(II), Mn(II), etc.; Z = Al, Fe(III), Cr(III), V(III) etc.; Trace amounts of Sn may replace Fe(III)
    Polymorphs:
Afghanistan, Jegdalek

Record No:    148

Geology:    Ruby in situ in metamorphosed dolomitic limestone cut by granitic intrusions of Oligocene age

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Brückl, K. (1937) Die Minerallagerstätten von Östafghanistan. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, B-Bd 72, Abt. A, H 1, pp. 1–97; RWHL* see pp.
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Not Specified - X₃Z₂(SiO₄)₃
    Notes:X = Mg, Ca, Fe(II), Mn(II), etc.; Z = Al, Fe(III), Cr(III), V(III) etc.; Trace amounts of Sn may replace Fe(III)
    Polymorphs:
Myanmar (Burma), Mogok

Record No:    149

Geology:    Ruby occurs in contact or regionally metamorphosed limestones cut by clay bands

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL* see pp. 103
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Not Specified - X₃Z₂(SiO₄)₃
    Notes:X = Mg, Ca, Fe(II), Mn(II), etc.; Z = Al, Fe(III), Cr(III), V(III) etc.; Trace amounts of Sn may replace Fe(III)
    Polymorphs:
Sri Lanka (Ceylon),

Record No:    150

Geology:    Alluvial gravels derived from source rocks formed via granulite facies metamorphism. It is thought that intrusions of basic charnockites of basaltic chemistry into the Al-rich sediments caused their desilication, resulting in the formation of corundum

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1948) Gemstone inclusions. Journal of Gemmology, Vol. 2, No. 7, July, pp. 7–39; RWHL* see pp. 285
Garnet Group - Isometric
Solid Type:  Solid–Primary
  • Not Specified - X₃Z₂(SiO₄)₃
    Notes:X = Mg, Ca, Fe(II), Mn(II), etc.; Z = Al, Fe(III), Cr(III), V(III) etc.; Trace amounts of Sn may replace Fe(III)
    Polymorphs:
Tanzania, Winza

Record No:    151

Geology:    Ruby from primary and eluvial deposits associated with amphibolitic rock dikes

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Schwarz, D., Pardieu, V. et al. (2008) Rubies and sapphires from Winza, central Tanzania. Gems & Gemology, Vol. 44, No. 4, Winter, pp. 322–347; RWHL* see pp. 332, 335–336
Garnet Group - Isometric
Solid Type:  Solid–Primary
Thailand/Cambodia, Chanthaburi/Trat/Pailin

Record No:    152

Geology:    Sapphires and rubies found in eluvial and alluvial gravels derived from alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. (1971) New analytical results of the inclusions in Siam rubies. Journal of Gemmology, Vol.  12, No.  7, July, pp. 242–252; RWHL* see pp. 244–246
Gibbsite - Monoclinic
Solid Type:  Solid–Primary
  • Gibbsite Monoclinic Al(OH)₃
    Notes:
    Polymorphs:Bayerite, Doyleite, Nordstrandite, UM1990-28-OHF:Al
Myanmar (Burma), Mogok

Record No:    153

Geology:    Sapphires occur in primary or alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Soonthorntanikul, W., Vertriest, W. et al. (2017) An in-depth gemological study of blue sapphires from the Baw Mar mine (Mogok, Myanmar). GIA News from Research, February, 87 pp.; RWHL* see pp. 40
Gibbsite - Monoclinic
Solid Type:  Solid–Primary
  • Gibbsite Monoclinic Al(OH)₃
    Notes:
    Polymorphs:Bayerite, Doyleite, Nordstrandite, UM1990-28-OHF:Al
USA (Montana), Rock Creek

Record No:    154

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Unknown

References:
  • Zwaan, J.C., Buter, E. et al. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry, and indications of a metamorphic origin. Gems & Gemology, Vol. 51, No. 4, Winter, pp. 370–391; RWHL* see pp. 379
Glass - Amorphous
Solid Type:  Solid–Primary
USA (Montana), Rock Creek, Missouri River, Yogo

Record No:    155

Geology:    Sapphire in alluvials believed derived from igneous dikes of unknown composition

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Rare

References:
  • Gübelin, E.J. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 230
Grandidierite - Orthorhombic
Solid Type:  Solid–Primary
  • Grandidierite Orthorhombic (Mg,Fe²⁺)(Al,Fe³⁺)₃(SiO₄)(BO₃)O₂
Madagascar,

Record No:    156

Geology:   

Origin Confidence:    4: Submitted to lab for testing/research

Frequency Seen:    Rare

References:
  • Hain, M. and Hughes, E.B. (2019) MicroWorld: Grandidierite inclusions in sapphires. Gems & Gemology, Vol. 55, No. 1, Spring, pp. 111–112; RWHL* see pp. 111–112
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Afghanistan, Jegdalek

Record No:    157

Geology:    Ruby in situ in metamorphosed dolomitic limestone cut by granitic intrusions of Oligocene age

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

References:
  • Brückl, K. (1937) Die Minerallagerstätten von Östafghanistan. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, B-Bd 72, Abt. A, H 1, pp. 1–97; RWHL* see pp.

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