Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
sedimentary
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
mineral
Pickled Dragon Eggs (Fictional Interpretation: Purple Agate or Amethyst Geodes)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Pyrite (Cube variety)
Iron Sulfide (FeS2)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Moonstone
Orthoclase (KAlSi3O8), specifically the variety showing adularescence
mineral
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
mineral
Larimar
Pectolite (Blue variety), NaCa2Si3O10(OH)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Emerald In Matrix
Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium
mineral
Opal
Hydrated Silica (SiO2·nH2O)
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Epidote
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
metamorphic
Aquamarine (Rough)
Beryl (Be3Al2Si6O18)
mineral
Black Opal
Hydrated Silica (SiO2·nH2O)
mineral
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium)
mineral
Limonite with Opal infusion
FeO(OH)·nH2O (Limonite) / SiO2·nH2O (Opal)
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Amazonite
Microline Feldspar (KAlSi3O8)
mineral
Amethyst
Amethyst (Silicon Dioxide SiO2 + Fe4+)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Amazonite
K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)
Mineral
Hawk's Eye (Blue Tiger's Eye)
Quartz (fibrous crocidolite variety)
Mineral
Jasper with Agate Inclusions
Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate
sedimentary
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Mineral
Raw Emerald in Schist Matrix
Beryl (Be3Al2Si6O18) in Mica Schist
Mineral in Metamorphic Rock
Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
mineral
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)
mineral
Moonstone
Adularia (orthoclase) or Albite (plagioclase), a potassium aluminum silicate of the feldspar group
Mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
sedimentary
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Sedimentary / Metamorphic
Turquoise (with Hematite)
CuAl6(PO4)4(OH)8·4H2O
mineral
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Green Aventurine
Silicon dioxide with Fuscite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
mineral