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Solid Type Country/Origin
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    911

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 spinel

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

Frequency Seen:    Rare

References:
  • Gübelin, E.J. (1950) The diagnostic importance of inclusions in gemstones. Journal of Gemmology, Vol. 2, No. 7, July, pp. 281–303; RWHL* see pp. 290–291
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    912

Geology:   

Origin Confidence:    1: Collected at the mines

Frequency Seen:   

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. 671
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Tajikistan, Kuh-i-Lal

Record No:    913

Geology:    Spinel-​forsterite formations are confined only to magnesite marbles (CaO content 0.65–16​%) containing forsterite, graphite and pyrite

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

Frequency Seen:    Common

References:
  • Malsy, A.-K. and Klemm, L. (2010) Distinction of gem spinels from the Himalayan mountain belt. CHIMIA, Vol. 64, No. 10, pp. 741–746; RWHL see pp. 743–744
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Vietnam, Luc Yen

Record No:    914

Geology:    Spinels found in alluvial Quaternary gravels derived from mineralized marble

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

Frequency Seen:    Occasional

References:
  • Koivula, J.I., Kammerling, R.C. and Fritsch, E. (1993) Gem News: Spinel from Vietnam. Gems & Gemology, Vol. 29, No. 3, Fall, pp. 213–214; RWHL see pp. 214
Zoisite - Orthorhombic
Solid Type:  Solid–Primary
  • Zoisite Orthorhombic Ca₂Al₃[Si₂O₇][SiO₄]O(OH)
Vietnam, Luc Yen

Record No:    915

Geology:    Spinels found in alluvial Quaternary gravels derived from mineralized marble

Origin Confidence:   

Frequency Seen:   

References:
  • Kleismantas, A., Zoysa, G.E. et al. (2017) Chemistry and gemological features of spinels from Sri Lanka and Vietnam. 35th International Gemmological Conference Proceedings, 8–19 October, Windhoek, Namibia, pp. 148–150; RWHL see pp. 149
Hematite Group - Trigonal
Solid Type:  Solid-Secondary
Kenya, Eastern Kenya near the border with Somalia

Record No:    918

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 683–685
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Kenya, Eastern Kenya near the border with Somalia

Record No:    919

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 683–685
Diaspore Group - Orthorhombic
Solid Type:  Solid-Secondary
  • Diaspore Orthorhombic AlO(OH)
    Notes:
    Polymorphs:Böhmite
Kenya, Eastern Kenya near the border with Somalia

Record No:    920

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686–688
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Kenya, Eastern Kenya near the border with Somalia

Record No:    921

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686–688
Pyrite Group - Isometric
Solid Type:  Solid–Primary
  • Pyrite Isometric FeS₂
    Notes:
    Polymorphs:Marcasite
Kenya, Eastern Kenya near the border with Somalia

Record No:    922

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Baryte (Barite) Group - Orthorhombic
Solid Type:  Solid–Primary
Kenya, Eastern Kenya near the border with Somalia

Record No:    923

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Covellite - Hexagonal
Solid Type:  Solid–Primary
Kenya, Eastern Kenya near the border with Somalia

Record No:    924

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Kenya, Eastern Kenya near the border with Somalia

Record No:    925

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Kenya, Eastern Kenya near the border with Somalia

Record No:    926

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Kenya, Eastern Kenya near the border with Somalia

Record No:    927

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Feldspar Group - Monoclinic
Solid Type:  Solid–Primary
  • Orthoclase Monoclinic K(AlSi₃O₈)
    Notes:
    Polymorphs:Kokchetavite, Microcline, Sanidine
Kenya, Eastern Kenya near the border with Somalia

Record No:    928

Geology:    Unknown; presumably derived from alkali basalts

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

Frequency Seen:    Common

References:
  • Bui, T.N., Deliousi, K., Malik, T.K. and Corte, K., de (2015) From exsolution to 'gold sheen': A new variety of corundum. Journal of Gemmology, Vol. 34, No. 8, October, pp. 678–691; RWHL* see pp. 686
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Tanzania, Mahenge

Record No:    929

Geology:   

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

Frequency Seen:    Rare

References:
  • Lotusgemology.com Hyperion Inclusion Database; posted 4 June 2020 see pp.
Calcite Group - Trigonal
Solid Type:  Solid–Primary
Afghanistan, Unknown

Record No:    931

Geology:   

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

Frequency Seen:    Unknown

References:
  • Hyperion Inclusion Database, posted 6 Nov. 2019 see pp.
Graphite - Hexagonal
Solid Type:  Solid–Primary
  • Graphite Hexagonal C
    Notes:
    Polymorphs:Chaoite, Diamond, Lonsdaleite
Afghanistan, Unknown

Record No:    932

Geology:   

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

Frequency Seen:    Unknown

References:
  • Hyperion Inclusion Database, posted 6 Nov. 2019 see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Madagascar, Ilakaka

Record No:    933

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Lotus Hyperion Inclusion Database see pp.
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Madagascar, Ilakaka

Record No:    934

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Lotus Hyperion Inclusion Database see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Madagascar, Central area

Record No:    935

Geology:    Ruby, fancy and blue sapphire in secondary deposits associated with amphibolite

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

Frequency Seen:    Occasional

References:
  • Lotus Hyperion Inclusion Database, image uploaded 19 June 2020 see pp.
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Madagascar, Central area

Record No:    936

Geology:    Ruby, fancy and blue sapphire in secondary deposits associated with amphibolite

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

Frequency Seen:    Occasional

References:
  • Lotus Hyperion Inclusion Database, image uploaded 19 June 2020 see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    937

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. and Koivula, J.I. (2008) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL* see pp. 192
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    938

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

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

Frequency Seen:    Rare

References:
  • Lotus Hyperion Reference Database see pp.
Böhmite (Boehmite) - Orthorhombic
Solid Type:  Solid-Secondary
Mozambique, Montepuez

Record No:    939

Geology:    Primary and secondary ruby associated with amphibolite

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

Frequency Seen:    Common

References:
  • Lotus Gemology Hyperion Inclusion Database see pp.
Feldspar Group - Triclinic
Solid Type:  Solid–Primary
Pakistan (Kashmir), Batakundi

Record No:    940

Geology:    Ruby disseminated within marble or in veinlets/gash veins sometimes related to micro-shear zones

Origin Confidence:    3: Obtained in a secondary market

Frequency Seen:    Common

References:
  • Lotus Hyperion Inclusion Database see pp.
Zoisite - Orthorhombic
Solid Type:  Solid–Primary
  • Zoisite Orthorhombic Ca₂Al₃[Si₂O₇][SiO₄]O(OH)
Mozambique, Montepuez

Record No:    941

Geology:    Primary and secondary ruby associated with amphibolite

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

Frequency Seen:    Rare

References:
  • Lotus Gemology Hyperion Inclusion Database see pp.
Chlorite Group - Monoclinic
Solid Type:  Solid–Primary
  • Clinochlore Monoclinic Mg₅Al(AlSi₃O₁₀)(OH)₈
    Notes:
    Polymorphs:Mostly monoclinic (also triclinic or orthorhombic)
Mozambique, Montepuez

Record No:    942

Geology:    Primary and secondary ruby associated with amphibolite

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

Frequency Seen:    Occasional

References:
  • Lotus Gemology Hyperion Inclusion Database see pp.
Tourmaline Group - Trigonal
Solid Type:  Solid–Primary
  • Dravite Trigonal Na(Mg₃)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)
Tajikistan, Not specified

Record No:    943

Geology:   

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Lotus Hyperion Inclusion Database see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Tajikistan, Snezhny

Record No:    944

Geology:    Ruby found in mineralized zone of marbles

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

Frequency Seen:    Common

References:
  • Lotus Hyperion Inclusion Database see pp.
Kyanite - Triclinic
Solid Type:  Solid–Primary
  • Kyanite Triclinic Al₂(SiO₄)O
    Notes:
    Polymorphs:Andalusite, Sillimanite
Mozambique, Montepuez

Record No:    945

Geology:    Primary and secondary ruby associated with amphibolite

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

Frequency Seen:    Rare

References:
  • see pp.
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Vietnam, Luc Yen

Record No:    946

Geology:    Spinels found in alluvials or in mineralized marble. Red spinel typically comes from pure white calcitic/dolomitic marble, sometimes associated with clinochlore or phlogopite. Violet, purple, brown and blue spinels are found in marble with a more complex mineral assemblage containing clinohumite, pargasite, clinochlore and forsterite

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

Frequency Seen:    Rare

References:
  • Lotus Gemology Hyperion Database, posted 19 August 2020 see pp.
Bussyite-(Ce) - Monoclinic
Solid Type:  Solid-Secondary
  • Bussyite-(Ce) Monoclinic (Ce,REE)₃(Na,H₂O)₆MnSi₉Be₅(O,OH)₃₀F₄
    Notes:
    Polymorphs:Diaspore
Mozambique, Montepuez

Record No:    948

Geology:    Primary and secondary ruby associated with amphibolite

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

Frequency Seen:    Common

References:
  • Lotus Gemology Hyperion Inclusion Database, posted 28 August 2020 see pp.
Columbite Group - Orthorhombic
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    949

Geology:   

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp. see pp. 56
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
Not Specified,

Record No:    952

Geology:    Mica schist

Origin Confidence:    5: Unknown

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp. see pp. 165
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Not Specified,

Record No:    953

Geology:    Mica schist

Origin Confidence:    5: Unknown

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp. see pp. 165
Rutile Group - Tetragonal
Solid Type:  Solid-Secondary
  • Rutile Tetragonal TiO₂
    Notes:
    Polymorphs:Akaogiite, Anatase, Brookite, Riesite, TiO2 II, UM1991-08-O:Ti
Not Specified,

Record No:    954

Geology:    Not specified

Origin Confidence:    5: Unknown

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1973) Internal World of Gemstones. Zürich, ABC Verlag, reprinted 1983, 234 pp. see pp. 165
Pyroxene Group - Monoclinic
Solid Type:  Solid–Primary
Not specified,

Record No:    958

Geology:    Not specified

Origin Confidence:    5: Unknown

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL*. see pp. 172
Zircon Group - Tetragonal
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    959

Geology:   

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp. see pp. 169, 180
Quartz - Trigonal
Solid Type:  Solid–Primary
  • Quartz Trigonal SiO₂
    Notes:
    Polymorphs:Coesite, Cristobalite, Keatite, Mogánite, Seifertite, Stishovite, Tridymite
Czech Republic,

Record No:    960

Geology:    The Bohemian garnet has been mined for over 600 years mostly dug at the mines of Meronitz, and chiefly in the northwestern part of the Czech Republic. The garnets are found in a gravel or conglomerate, resulting from the decomposition of a serpentine.

Origin Confidence:    5: Unknown

Frequency Seen:    Common

References:
  • Gübelin, E.J. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL*. see pp. 173, 178
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
Tanzania, Maji moto, Lake Manyara

Record No:    962

Geology:    Biotite mica schist

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones, Volume 1. Basel, Switzerland, ABC Edition, 532 pp. see pp. 265
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Biotite Monoclinic K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg)([Si/Al]Si₂O₁₀)(OH/F)₂
Brazil, Not specified

Record No:    963

Geology:    Not specified

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones, Volume 1. Basel, Switzerland, ABC Edition, 532 pp. see pp. 266
Quartz - Trigonal
Solid Type:  Solid–Primary
  • Quartz Trigonal SiO₂
    Notes:
    Polymorphs:Coesite, Cristobalite, Keatite, Mogánite, Seifertite, Stishovite, Tridymite
Madagascar, Not specified

Record No:    964

Geology:    Not specified

Origin Confidence:   

Frequency Seen:   

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones, Volume 1. Basel, Switzerland, ABC Edition, 532 pp. see pp. 266
Ilmenite Group - Trigonal
Solid Type:  Solid-Secondary
  • Ilmenite Trigonal Fe²⁺TiO₃
    Notes:
    Polymorphs:Wangdaodeite
Sri Lanka (Ceylon), Not specified

Record No:    965

Geology:    Not specified

Origin Confidence:    5: Unknown

Frequency Seen:    Unknown

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones, Volume 1. Basel, Switzerland, ABC Edition, 532 pp. see pp. 412
Platinum - Isometric
Solid Type:  Solid–Primary
Chrysoberyl - Orthorhombic
Solid Type:  Solid–Primary
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Sri Lanka (Ceylon), Not specified

Record No:    970

Geology:    Not specified

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. see pp. 374
Calcite Group - Trigonal
Solid Type:  Solid–Primary
  • Calcite Trigonal CaCO₃
    Notes:
    Polymorphs:Aragonite, Vaterite
Brazil, Hematita

Record No:    972

Geology:   

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. see pp. 375–376
Fluorite Group - Isometric
Solid Type:  Solid–Primary
Brazil, Hematita

Record No:    973

Geology:   

Origin Confidence:    5: Unknown

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. see pp. 378
Mica Group - Monoclinic
Solid Type:  Solid–Primary
Mica Group - Monoclinic
Solid Type:  Solid–Primary
  • Not Specified -
Russia, Ural Mountains near Malysheva

Record No:    975

Geology:   

Origin Confidence:    5: Unknown

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. see pp. 380
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Australia,

Record No:    246

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

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. 348
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Cambodia, Pailin

Record No:    247

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

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

Frequency Seen:    Occasional

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. 187–188
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Nigeria, Jos area, Kaduna province

Record No:    250

Geology:    Sapphire in alluvial and residual deposits from alkali basalts

Origin Confidence:    3: Obtained in a secondary market

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. 438
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Madagascar, Ambondromifehy, Antsiranana Province

Record No:    251

Geology:    Sapphire in secondary deposits derived from alkali basalts

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

Frequency Seen:    Occasional

References:
  • Johnson, M.L. and Koivula, J.I. (1997) Gem News: Sapphires from northern Madagascar. Gems & Gemology, Vol. 33, No. 4, Winter, p. 305; RWHL see pp. 305
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Thailand (Siam), Chanthaburi

Record No:    252

Geology:   

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Saeseaw, S., Sangsawong, S. et al. (2017a) A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics. Gemological Institute of America, Bangkok, 12 April, 42 pp.; RWHL see pp. 16, 23
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
USA (Montana),

Record No:    253

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. 377, 379
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Vietnam, Lam Dong

Record No:    272

Geology:    Sapphires found in alluvial gravels derived from alkali basalts

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. 217
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Nigeria, Kaduna and Plateau States

Record No:    554

Geology:    Type 1C. Tectonic-magmatic-related, with subtypes hosted in granitic rocks: Emerald in pegmatitic pods

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

Frequency Seen:    Rare

References:
  • Schwarz, D., Kanis, J. and Kinnaird, J. (1996) Emerald and green beryl from Central Nigeria. Journal of Gemmology, Vol. 25, No. 2, April, pp. 117–141; RWHL* see pp. 129
Pyrochlore Supergroup - Isometric
Solid Type:  Solid–Primary
Brazil, Itabira-Nova Era Region (Belmont, Capoeirana, Piteiras Mines)

Record No:    732

Geology:    Type 1A. Tectonic-magnamtic related, with subtypes hosted in mafic-ultra-mafic rocks: Pegmatite-aplite-quartz-greisen veins, pods, metasomatites

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Duarte, L.d.C., Juchem, P.L., Pulz, G.M., Brum, T.M.M.d., Chodur, N., Liccardo, A., Fischer, A.C. and Acauan, R.B. (2003) Aplicações de microscopia eletrônica de varredura (MEV) e sistema de energia dispersiva (EDS) no estudo de gemas: exemplos brasileiros. Pesquisas em Geociências, Vol. 30, No. 2, Sept.–Dec., pp. 3–15; RWHL* see pp. 8
Sapphirine Supergroup - Monoclinic
Solid Type:  Solid–Primary
  • Sapphirine Monoclinic Mg₄(Mg₃Al₉)O₄[So₃Al₉O₃₆]
Greenland, Aappaluttoq

Record No:    311

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

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, 10
Sapphirine Supergroup - Monoclinic
Solid Type:  Solid–Primary
  • Sapphirine Monoclinic Mg₄(Mg₃Al₉)O₄[So₃Al₉O₃₆]
Thailand (Siam), Chanthaburi/Trat

Record No:    312

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Koivula, J.I. and Fryer, C.W. (1987) Sapphirine (not sapphire) in a ruby from Bo Rai, Thailand. Journal of Gemmology, Vol. 20, No. 6, April, pp. 369–370; RWHL see pp. 369–370
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
Mozambique, Montepuez

Record No:    323

Geology:    Primary and secondary ruby associated with amphibolite

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

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. 77
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    324

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.
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    325

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. 72–73
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Rwanda, Cyangugu

Record No:    326

Geology:    Sapphire in 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. 100
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
USA (Montana), Missouri River, Rock Creek

Record No:    327

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:
  • Garland, M.I. (2002) The Alluvial Sapphire Deposits of Western Montana. University of Toronto, Canada, PhD thesis, 562 pp.; RWHL* see pp. 5-79–80, 5-109, 5-111
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Australia, New England District, NSW

Record No:    328

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.
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
USA (Montana), Rock Creek

Record No:    329

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

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Garland, M.I. (2002) The Alluvial Sapphire Deposits of Western Montana. University of Toronto, Canada, PhD thesis, 562 pp.; RWHL* see pp. 5-109, 5-111
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Vietnam, Dak Nong

Record No:    330

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. 46–47
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Afghanistan, Jegdalek

Record No:    331

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.
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Not Specified - AD₂X₄
    Notes:A = Fe, Mn, Mg, Mn, Si, Ge, Co, Cu, Sb, Zn,Ti, Ni; D = Fe, Cr, V, Mn, Al, Co, In, Ir, Rh, Pt, Ni; X = O²⁻, S²⁻ or Se²⁻
    Polymorphs:
China, Fujian, Jiangsu

Record No:    332

Geology:    Sapphire in secondary deposits derived from alkali basalts

Origin Confidence:   

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. 371
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
India (Kashmir), Sumjam

Record No:    333

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

Origin Confidence:    3: Obtained in a secondary market

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; RWHL* see pp. 59–60
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Madagascar, Andranondambo

Record No:    334

Geology:    Sapphire in metamorphic skarn-type deposits

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

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. 183
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Myanmar (Burma), Mogok

Record No:    335

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. (1953) Inclusions as a Means of Gemstone Identification. Los Angeles, GIA, 220 pp.; RWHL* see pp. 103–104
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Pakistan, Hunza

Record No:    336

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
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    337

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:    Rare

References:
  • Gübelin, E.J. and Koivula, J.I. (1986) Photoatlas of Inclusions in Gemstones. Zurich, Switzerland, ABC Edition, 532 pp.; RWHL* see pp. 353–354
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Tanzania, Morogoro

Record No:    338

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

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

Frequency Seen:    Occasional

References:
  • Hänni, H.A. and Schmetzer, K. (1991) New rubies from the Morogoro area, Tanza­nia. Gems & Gemology, Vol. 27, No. 3, Fall, pp. 156–167; RWHL* see pp. 164
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Tanzania, Umba

Record No:    339

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:    Occasional

References:
  • Zwaan, P.C. (1974) Garnet, corundum, and other gem minerals from Umba, Tanza­nia. Scripta Geologica, Vol. 20, pp. 19–30; RWHL* see pp. 29
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Tanzania, Winza

Record No:    340

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. 335
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Thailand (Siam), Bo Ploi, Kanchanaburi

Record No:    341

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:
  • 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, 376
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Vietnam, Yen Bai

Record No:    342

Geology:    Rubies 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:    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. 188, 190
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
India, Karnataka

Record No:    345

Geology:    Ruby from deposits derived from anorthosite-gabbro ultramafic complexes

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Rare

References:
  • Panjikar, J. and Panjikar, A. (2016) Tialite (Al2TiO5) may cause asterism. ICGL Newsletter, No. 1, Summer, pp. 6–8; RWHL see pp. 6–8
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Zimbabwe, Sandawana

Record No:    500

Geology:    Type 1A. Tectonic-magmatic-related with subtypes hosted in mafic-ultramafic rocks: Emerald occurs in schist as a result of contact metasomatism at the border of ultramafic rocks and rare-element pegmatites during a deformation event, involving late stage magmatic/hydrothermal activity focused by shearing

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Gübelin, E.J. (1958) Emeralds from Sandawana. Journal of Gemmology, Vol. 6, No. 8, October, pp. 340–354; RWHL. see pp. 352
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Zambia, Kifubu area

Record No:    518

Geology:    Type 1A. Tectonic-magmatic-related with subtypes hosted in mafic-ultramafic rocks: Emerald occurs in primary and secondary deposits associated with biotite-phlogopite schists. Mineralization areas are confined almost entirely to phlogopite reaction zones adjacent to Be-bearing quartz-tourmaline pegmatite veins that metasomatically altered Cr-bearing metabasite host rocks

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Common

References:
  • Koivula, J.I. (1984) Mineral inclusions in Zambian emeralds. Australian Gemmologist, Vol. 15, No. 7, August, pp. 235–239; RWHL see pp. 236–237
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
South Africa, Transvaal

Record No:    606

Geology:    Type 1A. Tectonic-magmatic-related, with subtypes hosted in mafic-ultramafic rocks: Emerald is found in primary deposits in quartz veins in biotite schist

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. 396–397
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Not Specified - AD₂X₄
    Notes:A = Fe, Mn, Mg, Mn, Si, Ge, Co, Cu, Sb, Zn,Ti, Ni; D = Fe, Cr, V, Mn, Al, Co, In, Ir, Rh, Pt, Ni; X = O²⁻, S²⁻ or Se²⁻
    Polymorphs:
Madagascar, Mananjary

Record No:    636

Geology:    Type 1A. Tectonic-magmatic-related, with subtypes hosted in mafic-ultramafic rocks: Emeralds in a mica schist

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

Frequency Seen:    Rare

References:
  • Thomas, A. (1993) The emerald mines of Madagascar. South African Gemmologist, Vol. 7, No. 3, pp. 3–11; not seen see pp.
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
Brazil, Itabira-Nova Era Region (Belmont, Capoeirana, Piteiras Mines)

Record No:    655

Geology:    Type 1A. Tectonic-magnamtic related, with subtypes hosted in mafic-ultra-mafic rocks: Pegmatite-aplite-quartz-greisen veins, pods, metasomatites

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. 246
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Brazil, Santa Terezinha de Goiás

Record No:    659

Geology:    Type 2A. Tectonic-metamorphic related, with subtypes hosted in mafic-ultra-mafic rocks: Emeralds in a mica schist not associated with pegmatites

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

Frequency Seen:    Occasional

References:
  • Hänni, H.A. and Kerez, C.J. (1983) Neues vom Smaragd-Vorkommen von Sta. Terezinha de Goiás, Goiás, Brasilien. Zeitschrift der Deutschen Gemmologischen Gesellschaft, Vol. 32, No. 1, pp. 50–58; RWHL see pp. 55–56
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Austria, Habach Valley

Record No:    673

Geology:    Type 2A. Tectonic-metamorphic-related, with emerald mined in primary deposits in mafic-ultramafic rocks (greenschist to granulite facies). Rarely Type 2D (metamorphosed Type 1 or hidden-granitic intrusion-related)

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Grundmann, G. (1991) Smaragd. extra-LAPiS, No. 1, Münich, Christian Weise Verlag, RWHL* see pp. 58
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
Austria, Habach Valley

Record No:    674

Geology:    Type 2A. Tectonic-metamorphic-related, with emerald mined in primary deposits in mafic-ultramafic rocks (greenschist to granulite facies). Rarely Type 2D (metamorphosed Type 1 or hidden-granitic intrusion-related)

Origin Confidence:    1: Collected at the mines

Frequency Seen:    Occasional

References:
  • Grundmann, G. (1991) Smaragd. extra-LAPiS, No. 1, Münich, Christian Weise Verlag, RWHL* see pp. 58
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Brazil, Santa Terezinha de Goiás

Record No:    727

Geology:    Type 2A. Tectonic-metamorphic related, with subtypes hosted in mafic-ultra-mafic rocks: Emeralds in a mica schist not associated with pegmatites

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

Frequency Seen:    Occasional

References:
  • Duarte, L.d.C., Juchem, P.L., Pulz, G.M., Brum, T.M.M.d., Chodur, N., Liccardo, A., Fischer, A.C. and Acauan, R.B. (2003) Aplicações de microscopia eletrônica de varredura (MEV) e sistema de energia dispersiva (EDS) no estudo de gemas: exemplos brasileiros. Pesquisas em Geociências, Vol. 30, No. 2, Sept.–Dec., pp. 3–15; RWHL* see pp. 8
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
Brazil, Socotó, Bahia State

Record No:    733

Geology:    Type 1A. Tectonic-magnamtic related, with subtypes hosted in mafic-ultra-mafic rocks: Pegmatite-aplite-quartz-greisen veins, pods, metasomatites

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

Frequency Seen:    Occasional

References:
  • Duarte, L.d.C., Juchem, P.L., Pulz, G.M., Brum, T.M.M.d., Chodur, N., Liccardo, A., Fischer, A.C. and Acauan, R.B. (2003) Aplicações de microscopia eletrônica de varredura (MEV) e sistema de energia dispersiva (EDS) no estudo de gemas: exemplos brasileiros. Pesquisas em Geociências, Vol. 30, No. 2, Sept.–Dec., pp. 3–15; RWHL* see pp. 8
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
  • Chromite Isometric Fe²⁺Cr³⁺₂O₄
    Notes:
    Polymorphs:Chenmingite, Xieite
Pakistan, Swat

Record No:    764

Geology:    Type 2D: Metamorphosed Type 1 deposits or hidden granitic instrusion-related and some unclassified deposits

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. 420–424
Spinel Supergroup - Isometric
Solid Type:  Solid-Secondary
Sri Lanka (Ceylon),

Record No:    875

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 spinel

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

Frequency Seen:    Occasional

References:
  • Eppler, W.F. (1958) Notes on asterism in spinel and chatoyancy in chrysoberyl, quartz, tourmaline, zircon and scapolite. Journal of Gemmology, Vol. 6, No. 6, April, pp. 251–263; RWHL* see pp. 251
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Madagascar,

Record No:    878

Geology:   

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

Frequency Seen:   

References:
  • Milisenda, C., Henn, U. et al. (2001) New gemstone occurrences in the south-west of Madagascar. Journal of Gemmology, Vol. 27, No. 7, July, pp. 385–394; RWHL see pp. 392
Spinel Supergroup - Isometric
Solid Type:  Solid–Primary
Sri Lanka (Ceylon),

Record No:    880

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 spinel

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

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. 700

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