Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Category
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Fluorite
Calcium Fluoride (CaF2)
Pyrite
Iron Disulfide (FeS2)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Banded Calcite
Calcium Carbonate (CaCO3)
Calcite
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (Mainly SiO2)
Black Onyx
Black Chalcedony (SiO2)
Eudialyte
Eudialyte (Na4(Ca,Ce)2(Fe2+,Mn,Y)ZrSi8O22(OH,Cl)2)
Soapstone
Steatite (composed primarily of Talc: Mg3Si4O10(OH)2)
White Chalcedony (Agate)
Silicon Dioxide (SiO2)
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Onyx Marble (also commonly called Onyx)
Calcite (CaCO3), often with other mineral impurities
Orange Calcite
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (SiO2)
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
Red Coral (with Hematite and Black Pearl accents)
Corallium rubrum (Calcium Carbonate, CaCO3)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Quartzite
Quartzite (SiO2)
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
Onyx (Black Onyx)
Silicon Dioxide (SiO2)
Banded Calcite (often sold as Onyx)
Calcite (Calcium Carbonate, CaCO3)
Thulite in Matrix
Pink Zoisite - Ca2Al3(SiO4)3(OH)
Rhodonite
Rhodonite (Manganese Silicate), chemical formula: (Mn,Fe,Mg,Ca)SiO3
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Rhodochrosite
Manganese carbonate (MnCO3)
Fossiliferous Limestone with Crinoid stems
Calcite-rich Biogenic Sedimentary Rock (CaCO3)
Zebra Marble
Metamorphosed Alabaster/Limestone (CaCO3)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Chalk / Sedimentary Limestone
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
Celestite (Celestine)
Strontium sulfate (SrSO4)
Azurite
Azurite (Cu3(CO3)2(OH)2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Sandstone
Arenite (primarily SiO2)