Marble
Recrystallized Calcite (CaCO3)
Category
Browse crystal specimens identified by the Rock Identifier community.
Marble
Recrystallized Calcite (CaCO3)
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Pyrite (on Quartz/Sulfide matrix)
Iron Sulfide (FeS2)
Rough Amethyst Quartz
Silicon Dioxide with Iron impurities (SiO2)
Kidney Stone
Calcium Oxalate (CaC2O4), Uric Acid, or Struvite
Garnet-bearing Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
Quartz Geode (Cracked Open Fragment)
Silicon Dioxide (SiO2)
Granite Cobble
Plutonic Granite
Amethyst Cluster
Amethyst (Silicon Dioxide), chemical formula: SiO2
Granite
Granite (Phaneritic Igneous Rock)
Granite
Phaneritic Plutonic Felsic Rock
Granite
Granite (Felsic Plutonic Rock, consisting primarily of Quartz, Feldspar, and Mica)
Yellow Calcite
Calcium Carbonate (CaCO3)
Milky Quartz/Clear Quartz Cluster
Silicon Dioxide (SiO2)
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Titanium Aura Quartz (Aura Quartz)
Titanium-coated Silicon Dioxide (SiO2)
Amethyst Geode (Thunderegg)
Silicon Dioxide (SiO2) - Quartz Variety: Amethyst
Quartz Geode
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Diamond (in Gold Jewelry)
Carbon (C)
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Granite with Biotite and Quartz
Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, and K(Mg,Fe)3AlSi3O10(OH)2)
Epidote
Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)
Granite
Phaneritic Felsic Intrusive Igneous Rock
Agate Geode
Chalcedony (SiO2 - Silicon Dioxide)
Beryl (likely Aquamarine) in matrix
Be3Al2(SiO3)6 (Beryllium Aluminum Silicate)
Marble
Recrystallized Calcite Rock (CaCO3)
Red Jasper
Silicon Dioxide with Hematite (SiO2 + Fe2O3)
Pyrite with Calcite
Iron Disulfide (FeS2) with Calcium Carbonate (CaCO3)
Smoky Quartz
Silicon Dioxide (SiO2)
Rough Citrine Quartz
Citrine (Silicon Dioxide, SiO2 with iron impurities)
Labradorite (Gray Tumbled)
Labradorite (Ca,Na)(Al,Si)4O8
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
Garnet
Garnet Group (Silicate mineral); general formula X3Y2(SiO4)3
Granite (including Pegmatite variants)
Phaneritic Plutonic Rock (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Muscovite mica)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Clear Quartz
Silicon dioxide (SiO2)
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
Labradorite
Labradorite (Ca,Na)(Al,Si)4O8