Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Amazonite
Microcline (KAlSi3O8) with Pb trace impurities
Rhodochrosite
Manganese carbonate (MnCO3)
Amazonite in Pegmatite Matrix with Smoky Quartz
K(AlSi3O8) - Microcline (var. Amazonite) with SiO2 (Quartz)
Pyrite
Iron Sulfide (FeS2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Epidote
Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Jasper
Silicon dioxide (SiO2)
Rough Amber (likely Copal or immature Amber)
Organic gemstone / Succinite (if Baltic)
Moonstone with Black Tourmaline
Feldspar (KAlSi3O8) with inclusions of Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Amber
Succinicum (C10H16O)
Iron-rich weathered rock, possibly goethite/limonite-bearing sandstone or ironstone
Limonite (hydrated iron oxides; chiefly goethite, FeO(OH), with hematite, Fe₂O₃)
Amber (Copal)
Fossilized Tree Resin
Yellow Jasper
Silicon Dioxide (SiO2) with goethite/iron oxide inclusions
Possible iron-stained quartzite or sandstone fragment
Quartzite (mostly SiO₂), possibly ferruginous sandstone
Dumortierite in Quartz
Silicon Dioxide with Aluminium Borosilicate (SiO2 + (Al,Fe7+)7(BO3)(SiO4)3O3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pyrite (Iron Pyrites)
Iron Sulfide (FeS2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Bloodstone / Heliotrope
Cryptocrystalline Quartz (SiO2 with inclusions)
Fossil Coral / Bryozoan
Anthozoa or Bryozoa indet. (Calcite/Silica)
Polished green aventurine (likely)
Quartz, SiO₂, with green mica or other mineral inclusions; the photo alone cannot confirm the exact stone.
Amber
Organic gemstone (Succinite)
Turquoise in Matrix
Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)
Green Fluorite
Calcium Fluoride (CaF2)
Moonstone with Black Tourmaline
Feldspar (Orthoclase/Adularia) with Schorl inclusions, KAlSi3O8
Malachite in Host Rock
Malachite - Cu2CO3(OH)2
Pyrite and Calcite (or Barite) Specimen
Iron Sulfide (FeS2) with Calcium Carbonate (CaCO3)
Serpentinite
Serpentinite (Hydrated magnesium iron silicate)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Red Jasper (possibly banded Jaspilite)
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Amber
Succinite (a fossilized organic resin)
Smoky Quartz
Silicon Dioxide (SiO2)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Feldspar-rich Pegmatite
Granitic Pegmatite (principally KAlSi3O8)
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
Jasper
Microcrystalline quartz (SiO2)
Lazulite
Lazulite (MgAl2(PO4)2(OH)2)
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
Epidote with Magnetite/Hematite inclusions
Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides