Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
mineral
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
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Carnelian Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
mineral
Chert / River Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint variation)
Chert (SiO2)
sedimentary
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Sedimentary / Metamorphic
Agate (Yellow Moss Agate)
Cryptocrystalline Quartz (SiO2)
mineral
Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
mineral
Lake Superior Agate
Silicon Dioxide (Cryptocrystalline Quartz), SiO2
mineral
Astrophyllite
Astrophyllite (K2NaFe7Ti2Si8O26(OH)4F)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silica / Silicon Dioxide - SiO2)
mineral
Ferruginous Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Fossiliferous Shale
Laminated Mudrock with plant fossils
sedimentary
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
metamorphic
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
sedimentary
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Malachite in Matrix
Copper Carbonate Hydroxide (Cu2CO3(OH)2)
mineral
Ferruginous Sandstone with Concretion
Sandstone (SiO2 dominated with Fe2O3 cement)
sedimentary
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Mineral
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
mineral
Garnet
Pyrope or Almandine (X3Y2(SiO4)3)
mineral
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Chalcedony variant)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
sedimentary
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
sedimentary
Fluorite with Quartz
Fluorite (CaF2) and Quartz (SiO2)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
sedimentary
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary