Coming Soon Search Module

by E. Billie Hughes

Working On Coming Soon Search Module

Show Hide advanced search

Solid Type Country/Origin
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Myanmar (Burma), Mogok

Record No:    158

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

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

Frequency Seen:    Occasional

References:
  • Kammerling, R.C., Scarratt, K. et  al. (1994) Myanmar and its gems—An update. Journal of Gemmology, Vol. 24, No. 1, pp.  3–40; RWHL* see pp. 26
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Sri Lanka (Ceylon),

Record No:    159

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:    Common

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 352–353
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Tanzania, Umba

Record No:    160

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Zwaan, P.C. (1974) Garnet, corundum, and other gem minerals from Umba, Tanza­nia. Scripta Geologica, Vol. 20, pp. 19–30; RWHL* see pp. 26, 29
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
USA (Montana), Rock Creek

Record No:    161

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. 379
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Vietnam, Yen Bai

Record No:    162

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. 193
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Vietnam, Dak Nong province

Record No:    163

Geology:    Alluvial deposits derived from alkali basalts

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

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. 52, 62
Halite Group - Isometric
Solid Type:  Solid–Primary
Vietnam, Yen Bai

Record No:    164

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. 193
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Corundum Trigonal Al₂O₃
    Notes:
    Polymorphs:Deltalumite, UM1990-23-O:Al, UM1990-24-O:Al, UM1995-15-O:Al, UM1996-16-O:Al, Unnamed (gamma-alumina)
Greenland, Aappaluttoq

Record No:    165

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
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Corundum Trigonal Al₂O₃
    Notes:
    Polymorphs:Deltalumite, UM1990-23-O:Al, UM1990-24-O:Al, UM1995-15-O:Al, UM1996-16-O:Al, Unnamed (gamma-alumina)
Myanmar (Burma), Mogok

Record No:    166

Geology:    Ruby occurs in contact or regionally metamorphosed limestones cut by clay bands. Sapphires occur in alluvial deposits derived from granitic pegmatites, or rarely corundum syenites

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL* see pp. 103
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Corundum Trigonal Al₂O₃
    Notes:
    Polymorphs:Deltalumite, UM1990-23-O:Al, UM1990-24-O:Al, UM1995-15-O:Al, UM1996-16-O:Al, Unnamed (gamma-alumina)
Sri Lanka (Ceylon),

Record No:    167

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:
  • Gübelin, E.J. (1940) Characteristics of Ceylon rubies. Gems & Gemology, Vol. 1, No. 8, pp. 121–124; RWHL see pp. 124
Hematite Group - Trigonal
Solid Type:  Solid–Primary
Unknown,

Record No:    168

Geology:   

Origin Confidence:   

Frequency Seen:   

References:
  • Zhou, W. (2017) Synthetic ruby with eskolaite inclusion. SSEF Facette, No. 23, February, p. 23; RWHL. see pp. 23
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Afghanistan, Jegdalek

Record No:    169

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:
  • Barthoux, J. (1933) Lapis-lazuli et rubis balais des cipolins afghans. Comptes Rendus de l’Academie des Sciences de France, Vol. 196, 10 April, pp.  1131–1134; RWHL see pp. 1133
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
India (Kashmir), Sumjam

Record No:    170

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Bui, H.N., Fritsch, E. et al. (2013) Kashmir sapphires: Geographical origin determination of top-quality blue sapphires versus science. International Gemmological Conference Proceedings, Hanoi, Vietnam, pp. 59–60; RWH see pp. 60
Hematite Group - Trigonal
Solid Type:  Solid-Secondary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Rwanda, Cyangugu

Record No:    171

Geology:    Sapphire in deposits associated with alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:   

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. 98–99
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Sri Lanka (Ceylon),

Record No:    172

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:   

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL*. see pp. 124, 134
Hematite Group - Trigonal
Solid Type:  Solid-Secondary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Tanzania, Umba

Record No:    173

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:    Common

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. 282–283
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
USA (Montana), Rock Creek

Record No:    174

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

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

Frequency Seen:    Occasional

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. 8, 10
Hematite Group - Trigonal
Solid Type:  Solid–Primary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Vietnam, Yen Bai

Record No:    175

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. 193
Hematite Group - Trigonal
Solid Type:  Solid-Secondary
  • Hematite Trigonal Fe₂O₃
    Notes:
    Polymorphs:Luogufengite, Maghemite
Vietnam, Dak Lak, Dak Nong

Record No:    176

Geology:    Sapphires found in alluvial gravels derived from alkali basalts

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

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. 46
Humite Group - Orthorhombic
Solid Type:  Solid–Primary
  • Humite Orthorhombic (Mg,Fe²⁺)₇(SiO₄)₃(F,OH)₂
Afghanistan, Jegdalek

Record No:    177

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Barthoux, J. (1933) Lapis-lazuli et rubis balais des cipolins afghans. Comptes Rendus de l’Academie des Sciences de France, Vol. 196, 10 April, pp.  1131–1134; RWHL see pp. 1133
Humite Group - Monoclinic
Solid Type:  Solid–Primary
Afghanistan, Jegdalek

Record No:    178

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Barthoux, J. (1933) Lapis-lazuli et rubis balais des cipolins afghans. Comptes Rendus de l’Academie des Sciences de France, Vol. 196, 10 April, pp.  1131–1134; RWHL see pp. 1133
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Australia,

Record No:    179

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:
  • Moon, A.R. and Phillips, M.R. (1984) An electron microscope study of exsolved phases in natural black Australian sapphire. Micron and Microscopica Acta, Vol. 15, No. 3, pp. 143–146; RWHL see pp. 144–145
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Laos, Huay Xai

Record No:    180

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

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

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. 45
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Madagascar, Andapa

Record No:    181

Geology:    Sapphire in secondary deposits derived from alkali basalts

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

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. 45
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Myanmar (Burma), Mogok

Record No:    182

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. 28–29, 36, 38
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Rwanda, Cyangugu

Record No:    183

Geology:    Sapphire in deposits associated with alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

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. 98–99
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Sri Lanka (Ceylon), Elahera

Record No:    184

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:
  • Gunawardene, M. and Rupasinghe, M.S. (1986) The Elahera gem field in central Sri Lanka. Gems & Gemology, Vol. 22, No. 2, Summer, pp. 80–95; RWHL see pp. 86
Ilmenite Group - Trigonal
Solid Type:  Solid–Primary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Thailand (Siam), Bo Ploi, Kanchanaburi

Record No:    185

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

Origin Confidence:    1: Collected at the mines

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. 45
Ilmenite Group - Trigonal
Solid Type:  Solid–Primary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
USA (Montana), Dry Cottonwood, Rock Creek

Record No:    186

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

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

Frequency Seen:    Occasional

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. 377, 379
Ilmenite Group - Trigonal
Solid Type:  Solid–Primary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Vietnam, Yen Bai

Record No:    187

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:    Occasional

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. 191
Ilmenite Group - Trigonal
Solid Type:  Solid–Primary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Vietnam, Dak Lak

Record No:    188

Geology:    Sapphires found in 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. 45
Kaolinite-Serpentine Group - Triclinic
Solid Type:  Solid–Primary
Thailand/Cambodia, Chanthaburi/Trat

Record No:    189

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:   

References:
  • Sangsawong, S., Vertriest, W. et al. (2017) A Study of Rubies from Cambodia & Thailand. Gemological Institute of America, Bangkok, August 7, Version 3, 37 pp.; RWHL* see pp. 20, 31
Kyanite - Triclinic
Solid Type:  Solid–Primary
  • Kyanite Triclinic Al₂(SiO₄)O
    Notes:
    Polymorphs:Andalusite, Sillimanite
Tanzania, Umba

Record No:    190

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:    Rare

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. 275
Marcasite Group - Orthorhombic
Solid Type:  Solid–Primary
Afghanistan, Jegdalek

Record No:    191

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

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

Frequency Seen:    Occasional

References:
  • Bowersox, G.W., Foord, E.E., Laurs, B.L., Shigley, J.E. and Smith, C.P. (2000) Ruby and sapphire from Jegdalek, Afghanistan. Gems & Gemology, Vol. 36, No. 2, Summer, pp. 110–126; RWHL* see pp. 120–121
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
India (Kashmir), Sumjam

Record No:    192

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:    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. 198
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
Madagascar, Andranondambo

Record No:    193

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Schwarz, D., Petsch, E.J. et al. (1996) Sapphires from the Andranondambo region, Madagascar. Gems & Gemology, Vol. 32, No. 2, pp. 80–99; RWHL* see pp. 90–91
Hematite Group - Trigonal
Solid Type:  Solid-Secondary
Madagascar, Andranondambo

Record No:    194

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Schwarz, D., Petsch, E.J. et al. (1996) Sapphires from the Andranondambo region, Madagascar. Gems & Gemology, Vol. 32, No. 2, pp. 80–99; RWHL* see pp. 92
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    195

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:    Common

References:
  • Gübelin, E.J. (1940) Characteristics of Ceylon rubies. Gems & Gemology, Vol. 3, No. 8, pp. 121–124; RWHL see pp. 124
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
USA (Montana), Dry Cottonwood, Rock Creek, Yogo

Record No:    196

Geology:    Yogo: Sapphire in situ and from alluvials derived from a lamprophyric rock intruded into limestone; Other: 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:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 346
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mong Hsu

Record No:    197

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. 16
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    198

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

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

Frequency Seen:    Common

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. 7–8, 11
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Mozambique, Montepuez

Record No:    199

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. 42, 52–63
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Tajikistan, Snezhny

Record No:    200

Geology:    Ruby found in mineralized zone of marbles

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

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. 171
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Margarite Monoclinic CaAl₂(Al₂Si₂O₁₀)(OH)₂
Tajikistan, Snezhny

Record No:    201

Geology:    Ruby found in mineralized zone of marbles

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

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. 168, 170
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Kenya, Mangari

Record No:    202

Geology:    Ruby derived from desilicated pegmatites cutting serpentinite (Penny Lane mine) and contact between the serpentinite and the pegmatite (John Saul mine)

Origin Confidence:   

Frequency Seen:   

References:
  • Hunstiger, C. (1989–90) Darstellung und Vergleich primärer Rubinvorkommen in metamorphen Muttergesteinen [Presentation and comparison of primary ruby occur­rences in metamorphic rock]. Zeitschrift der Deutschen Gemmologischen Gesellschaft, Part I: Petrographie und Phasenpetrologie, Vol. 38, No. 4, pp. 113–138; Part II: Petrographie und Phasenpetrologie, Vol. 39, No. 1, pp. 49–63; Part III: Petrographie und Phasenpetrologie, No. 2/3, pp. 121–145; RWHL* see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    203

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

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

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL* see pp. 102–103
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    204

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:    Common

References:
  • Gübelin, E.J. (1940) Characteristics of Ceylon rubies. Gems & Gemology, Vol. 3, No. 8, pp. 121–124; RWHL see pp. 124
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Tanzania, Tunduru

Record No:    205

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. 22–23
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Thailand (Siam), Bo Ploi, Kanchanaburi

Record No:    206

Geology:   

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. 57
Mica Group - Monoclinic
Solid Type:  Solid–Primary
USA (Montana), Dry Cottonwood, Rock Creek, Yogo

Record No:    207

Geology:    Yogo: Sapphire in situ and from alluvials derived from a lamprophyric rock intruded into limestone; other: 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. 378–379
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Vietnam, Yen Bai, Quy Chau

Record No:    208

Geology:    Yen Bai: Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself; Quy Chau: Rubies found in alluvial gravels from unknown source rocks (probably marble)

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. 57
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Greenland, Aappaluttoq

Record No:    209

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. 9
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Kenya, Mangari

Record No:    210

Geology:    Ruby derived from desilicated pegmatites cutting serpentinite (Penny Lane mine) and contact between the serpentinite and the pegmatite (John Saul mine)

Origin Confidence:   

Frequency Seen:   

References:
  • Hunstiger, C. (1989–90) Darstellung und Vergleich primärer Rubinvorkommen in metamorphen Muttergesteinen [Presentation and comparison of primary ruby occur­rences in metamorphic rock]. Zeitschrift der Deutschen Gemmologischen Gesellschaft, Part I: Petrographie und Phasenpetrologie, Vol. 38, No. 4, pp. 113–138; Part II: Petrographie und Phasenpetrologie, Vol. 39, No. 1, pp. 49–63; Part III: Petrographie und Phasenpetrologie, No. 2/3, pp. 121–145; RWHL* see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Madagascar, Andranondambo

Record No:    211

Geology:    Sapphire in metamorphic skarn-type deposits

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Schwarz, D., Petsch, E.J. et al. (1996) Sapphires from the Andranondambo region, Madagascar. Gems & Gemology, Vol. 32, No. 2, pp. 80–99; RWHL* see pp. 88, 90–91
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    212

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:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 120
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Tanzania, Tunduru

Record No:    213

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. 12–13
Mica Group - Monoclinic
Solid Type:  Solid–Primary
USA (Montana),

Record No:    214

Geology:   

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. 378–379
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Australia,

Record No:    215

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:    Unknown

References:
  • Coldham, T.S. (1985) Sapphires from Australia. Gems & Gemology, Vol. 21, No. 3, Fall, pp. 130–146; RWHL* see pp. 143
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Madagascar, Marosely

Record No:    216

Geology:    Ruby & sapphire in alluvial deposits of metamorphic origin

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

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
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Mozambique, Montepuez

Record No:    217

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. 42, 52–63
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Pakistan, Hunza

Record No:    218

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

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
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Rwanda, Cyangugu

Record No:    219

Geology:    Sapphire in deposits associated with alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Unknown

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
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Thailand (Siam), Chanthaburi

Record No:    220

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:
  • 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, 24
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Vietnam, Yen Bai, Quy Chau

Record No:    221

Geology:    Yen Bai: Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself; Quy Chau: Rubies found in alluvial gravels from unknown source rocks (probably marble)

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

Frequency Seen:    Unknown

References:
  • Kane, R.E., McClure, S.F. et  al. (1991) Rubies and fancy sapphires from Vietnam. Gems & Gemology, Vol. 27, No. 3, pp. 136–155; RWHL* see pp. 152
Molybdenite Group - Hexagonal
Solid Type:  Solid–Primary
  • Molybdenite Hexagonal MoS₂
    Notes:
    Polymorphs:Molybdenite-2H (common) and Molybdenite-3R (rare)
Thailand (Siam), Chanthaburi

Record No:    223

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

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, 24
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Rwanda, Cyangugu

Record No:    224

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. 100–101
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
Sri Lanka (Ceylon),

Record No:    225

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:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 120
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    226

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:    Occasional

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

Record No:    227

Geology:   

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Tanzania, Tunduru

Record No:    228

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. 14–15
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Thailand (Siam), Bo Welu, Chanthaburi

Record No:    229

Geology:   

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. 356–357, 364
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Vietnam, Yen Bai

Record No:    230

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
Nahcolite - Monoclinic
Solid Type:  Solid–Primary
USA (Montana), Rock Creek

Record No:    231

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. 377, 379
Nordstrandite - Triclinic
Solid Type:  Solid–Primary
  • Nordstrandite Triclinic Al(OH)₃
    Notes:
    Polymorphs:Bayerite, Doyleite, Gibbsite, UM1990-28-OHF:Al
Vietnam, Yen Bai, Quy Chau

Record No:    232

Geology:    Yen Bai: Rubies found in alluvial Quaternary gravels derived from mineralized marble, or directly from the marble itself; Quy Chau: Rubies found in alluvial gravels from unknown source rocks (probably marble)

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Kane, R.E., McClure, S.F. et  al. (1991) Rubies and fancy sapphires from Vietnam. Gems & Gemology, Vol. 27, No. 3, pp. 136–155; RWHL* see pp. 151
Olivine Group - Orthorhombic
Solid Type:  Solid–Primary
  • Forsterite Orthorhombic Mg₂SiO₄
    Notes:
    Polymorphs:Ringwoodite, Wadsleyite
Myanmar (Burma), Mogok

Record No:    233

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 49, 114
Olivine Group - Orthorhombic
Solid Type:  Solid–Primary
  • Forsterite Orthorhombic Mg₂SiO₄
    Notes:
    Polymorphs:Ringwoodite, Wadsleyite
Thailand/Cambodia, Chanthaburi/Trat/Pailin

Record No:    234

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Gübelin, E.J. (1940) Differences between Burma and Siam rubies. Gems & Gemology, Vol. 3, No. 5, Spring, pp. 69–72; RWHL* see pp. 252
Pentlandite Group - Isometric
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    235

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Coenraads, R.R. (1992) 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
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Afghanistan, Jegdalek

Record No:    236

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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.
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Myanmar (Burma), Mogok

Record No:    237

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

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. 76
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Pakistan, Hunza

Record No:    238

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Sri Lanka (Ceylon),

Record No:    239

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:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL* see pp. 124
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Tanzania, Songea

Record No:    240

Geology:    Ruby and sapphire in secondary deposits of unknown origin

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

Frequency Seen:    Occasional

References:
  • Johnson, M.L., Koivula, J.I. et al. (1999) Gem News: Rubies from Songea. Gems & Gemology, Vol. 35, No. 4, Winter, p. 215; RWHL see pp. 215
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Madagascar, Ilakaka

Record No:    241

Geology:    Ruby & sapphire of virtually all colors in alluvial deposits of unknown metamorphic origin

Origin Confidence:    1: Collected at the mines

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. 134
Monazite Group - Monoclinic
Solid Type:  Solid–Primary
Tanzania, Songea

Record No:    242

Geology:    Ruby and sapphire in secondary deposits of unknown origin

Origin Confidence:    1: Collected at the mines

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. 126
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Vietnam, Yen Bai

Record No:    244

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:    Occasional

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
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
USA (Montana), Yogo

Record No:    245

Geology:    Sapphire in situ and from alluvials derived from a lamprophyric rock intruded into limestone

Origin Confidence:    1: Collected at the mines

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
Pyroxene Group - Orthorhombic or Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - {Na}{Ca₂}{Mg₄Al}(Al₂Si₆O₂₂)(OH)₂
Greece, Aappaluttoq

Record No:    249

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
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
  • Augite Monoclinic (Ca,Na)(Mg,Fe²⁺,Al,Fe³⁺,Ti)[(Si,Al)₂O₆]
Myanmar (Burma), Mogok

Record No:    254

Geology:   

Origin Confidence:   

Frequency Seen:   

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp.; RWHL* see pp. 119
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
Thailand/Cambodia, Chanthatburi/Trat/Pailin

Record No:    255

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

Origin Confidence:   

Frequency Seen:   

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
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
USA (Montana),

Record No:    256

Geology:   

Origin Confidence:    5: Unknown

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. 224–225
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
Madagascar, Andranondambo

Record No:    257

Geology:    Sapphires in metamorphic skarn-type deposits

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Schwarz, D., Petsch, E.J. et al. (1996) Sapphires from the Andranondambo region, Madagascar. Gems & Gemology, Vol. 32, No. 2, pp. 80–99; RWHL* see pp. 90
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
Rwanda, Cyangugu

Record No:    258

Geology:    Sapphire in alluvial deposits associated with alkali basalts

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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
Pyroxene Group - Orthorhombic or Monoclinic
Solid Type:  Solid–Primary
  • Not Specified - {Na}{Ca₂}{Mg₄Al}(Al₂Si₆O₂₂)(OH)₂
Greenland, Aappaluttoq

Record No:    259

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
Pyrrhotite Group - Monoclinic
Solid Type:  Solid–Primary
Afghanistan, Jegdalek

Record No:    260

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Bowersox, G.W., Foord, E.E., Laurs, B.L., Shigley, J.E. and Smith, C.P. (2000) Ruby and sapphire from Jegdalek, Afghanistan. Gems & Gemology, Vol. 36, No. 2, Summer, pp. 110–126; RWHL* see pp. 120–121
Pyrrhotite Group - Monoclinic
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    261

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Coenraads, R.R. (1992) 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. 73
Pyrrhotite Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    262

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

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. 325
Pyrrhotite Group - Monoclinic
Solid Type:  Solid–Primary
Pakistan, Hunza, Nangimali

Record No:    263

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Pakistan (Kashmir), Nangimali

Record No:    264

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

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. 96
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Pakistan (Kashmir), Nangimali

Record No:    266

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

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. 96
Pyrrhotite Group - Monoclinic
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    267

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:    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. 161, 166, 177

Back to top