Rock Identifier

Category

Mineral (Silicate Replaced Organic Material)

Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pearl (Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3) — mineral

Pearl

Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3

Tiger's Eye (Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz) — Mineral

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz

Iron Slag (Anthropogenic Iron oxide/Silicate composite) — Mineral-like byproduct (Technogenic)

Iron Slag

Anthropogenic Iron oxide/Silicate composite

Mineral-like byproduct (Technogenic)

Fossilized Shark Tooth (Fossilized Elasmobranchii tooth (likely Odontaspis or Carcharias)) — sedimentary

Fossilized Shark Tooth

Fossilized Elasmobranchii tooth (likely Odontaspis or Carcharias)

Tiger's Eye (Pseudomorph of quartz after crocidolite (SiO2)) — metamorphic

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2)

Serpentinite (Serpentinite (complex silicate minerals including Lizardite, Antigorite, and Chrysotile)) — metamorphic

Serpentinite

Serpentinite (complex silicate minerals including Lizardite, Antigorite, and Chrysotile)

Pearls (Aragonite (calcium carbonate) and Conchiolin) — Mineraloid

Pearls

Aragonite (calcium carbonate) and Conchiolin

Granitoid (Granite/Gneiss) (Granitoid silicate rock, primarily quartz and feldspar) — igneous/metamorphic

Granitoid (Granite/Gneiss)

Granitoid silicate rock, primarily quartz and feldspar

igneous/metamorphic

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — Mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

White Marble (Recrystallized Calcite (CaCO3)) — metamorphic

White Marble

Recrystallized Calcite (CaCO3)

Amber (Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O) — mineral

Amber

Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O

Tree Agate (Dendritic Agate (Silicon Dioxide, SiO2)) — mineral

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2)

Basalt (Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)) — igneous

Basalt

Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — metamorphic

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Blue Tiger's Eye (Hawk's Eye) (Silicified Crocidolite (Pseudomorph of Quartz after Crocidolite), SiO2) — metamorphic

Blue Tiger's Eye (Hawk's Eye)

Silicified Crocidolite (Pseudomorph of Quartz after Crocidolite), SiO2

Tiger's Eye (Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)) — metamorphic

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)

Fossilized Dinosaur Skull (Tyrannosaurus rex) (Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica) — sedimentary

Fossilized Dinosaur Skull (Tyrannosaurus rex)

Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica

Green Jasper with Quartz veins (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Green Jasper with Quartz veins

Jasper (Silicon Dioxide, SiO2)

Chert (Chert (variant of microcrystalline quartz)) — Sedimentary

Chert

Chert (variant of microcrystalline quartz)

Amber (Black) (Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)) — Mineraloid

Amber (Black)

Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)

Slag (Industrial Glass Slag) (Amorphous Silica / Ferro-silicate Slag) — mineraloid / anthropogenic

Slag (Industrial Glass Slag)

Amorphous Silica / Ferro-silicate Slag

mineraloid / anthropogenic

Fuchsite (Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)) — mineral

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Peridot (Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)) — Mineral

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Eagle Eye Stone (Green Tiger's Eye) (Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)) — mineral

Eagle Eye Stone (Green Tiger's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Blue Tiger's Eye (Crocidolite in Quartz (altered)) — Mineral

Blue Tiger's Eye

Crocidolite in Quartz (altered)

Chert (Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper)

Silicon Dioxide (SiO2)

Shattuckite (Blue Quartz/Jasper Matrix) (Shattuckite (Copper Silicate Hydroxide - Cu5(SiO3)4(OH)2)) — mineral

Shattuckite (Blue Quartz/Jasper Matrix)

Shattuckite (Copper Silicate Hydroxide - Cu5(SiO3)4(OH)2)

Smoky Quartz on Feldspar (Granite Pegmatite) (Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)) — igneous

Smoky Quartz on Feldspar (Granite Pegmatite)

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)

Sandstone (likely Fossiliferous) (Arenite / Fossiliferous Sandstone (SiO2 composition)) — sedimentary

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Fuchsite with Ruby (Cr-rich Muscovite with Corundum (K(Al,Cr)2(AlSi3O10)(OH)2)) — metamorphic

Fuchsite with Ruby

Cr-rich Muscovite with Corundum (K(Al,Cr)2(AlSi3O10)(OH)2)

Moss Agate (Agate (Silicon Dioxide, SiO2) with dendritic inclusions) — sedimentary

Moss Agate

Agate (Silicon Dioxide, SiO2) with dendritic inclusions

Sandstone (Ferruginous) (Arenite (Fe2O3 rich)) — sedimentary

Sandstone (Ferruginous)

Arenite (Fe2O3 rich)

Glauconitic Sandstone (Greensand) (Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)

Fossil Coral (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Moss Agate (Silicon Dioxide with inclusions (SiO2)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2)

Unakite (Unakite Epidosite (composite of Epidote, Orthoclase, and Quartz)) — metamorphic

Unakite

Unakite Epidosite (composite of Epidote, Orthoclase, and Quartz)

Limonite (Iron Ore) (FeO(OH)·nH2O (Hydrous ferric oxide)) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Amethyst (Amethyst (Silica mineral, SiO2)) — mineral

Amethyst

Amethyst (Silica mineral, SiO2)

Rough Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rough Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Moss Agate (Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide

Echinoid Fossil (Commonly called a Sea Urchin or Heart Urchin) (Phylum Echinodermata, Class Echinoidea) — sedimentary

Echinoid Fossil (Commonly called a Sea Urchin or Heart Urchin)

Phylum Echinodermata, Class Echinoidea