Rock Identifier

Category

Organic Gemstone (Not A Rock)

Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.

Chert (Pink variety/Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Pink variety/Jasper)

Silicon Dioxide (SiO2)

Red Sandstone (Arenite (primarily Quartz, SiO2, with Iron Oxide/Hematite)) — sedimentary

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide/Hematite)

Basalt River Cobble (Basalt (Mafic Igneous Rock)) — igneous

Basalt River Cobble

Basalt (Mafic Igneous Rock)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — Mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Sandstone (Arenite (SiO2 principal)) — sedimentary

Sandstone

Arenite (SiO2 principal)

Ironstone Concretion (Iron-rich Mudstone) (Siderite / Geothite concretion (FeCO3 / FeO(OH))) — sedimentary

Ironstone Concretion (Iron-rich Mudstone)

Siderite / Geothite concretion (FeCO3 / FeO(OH))

Lapis Lazuli Globe (Complex mixture of Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite) — metamorphic

Lapis Lazuli Globe

Complex mixture of Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Chert (Common Opal/Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Common Opal/Chalcedony)

Microcrystalline Quartz (SiO2)

Bauxite (Concretionary) (Bauxite (Al(OH)3, AlO(OH))) — sedimentary

Bauxite (Concretionary)

Bauxite (Al(OH)3, AlO(OH))

Moss Agate Geode Sphere (Silicon Dioxide (SiO2) - Chalcedony with Chlorite or Manganese inclusions) — mineral

Moss Agate Geode Sphere

Silicon Dioxide (SiO2) - Chalcedony with Chlorite or Manganese inclusions

Basalt (Basalt (Mafic Extrusive)) — igneous

Basalt

Basalt (Mafic Extrusive)

Chalcopyrite (Chalcopyrite (CuFeS2)) — Mineral

Chalcopyrite

Chalcopyrite (CuFeS2)

Basalt (River Stone) (Basalt) — igneous

Basalt (River Stone)

Basalt

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Chert / Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper

Microcrystalline Quartz (SiO2)

Wishing Stone (Basalt/Greywacke with Quartz Vein) (Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion) — igneous/sedimentary

Wishing Stone (Basalt/Greywacke with Quartz Vein)

Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion

igneous/sedimentary

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Basalt (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Gold Flakes (Native Gold (Au)) — mineral

Gold Flakes

Native Gold (Au)

Muscovite on Quartz (Mica host rock) (KAl2(AlSi3O10)(OH)2 (Muscovite) in SiO2 (Quartz)) — igneous/metamorphic

Muscovite on Quartz (Mica host rock)

KAl2(AlSi3O10)(OH)2 (Muscovite) in SiO2 (Quartz)

igneous/metamorphic

Carnelian (Orange Chalcedony) (Silicon dioxide (SiO2)) — mineral

Carnelian (Orange Chalcedony)

Silicon dioxide (SiO2)

Amethyst (Amethyst (variety of Quartz, SiO2)) — mineral

Amethyst

Amethyst (variety of Quartz, SiO2)

Garnet (likely Almandine or a blend) (Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.) — Mineral

Garnet (likely Almandine or a blend)

Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.

Rock Salt (Halite) (Halite (Sodium Chloride, NaCl)) — mineral

Rock Salt (Halite)

Halite (Sodium Chloride, NaCl)

Chert (Jasper variation) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Banded Gneiss (Gneiss (High-grade Regional Metamorphic Rock)) — metamorphic

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Ironstone (with possible Hematite/Limonite coating) (Ironstone (Fe-rich sedimentary rock)) — sedimentary

Ironstone (with possible Hematite/Limonite coating)

Ironstone (Fe-rich sedimentary rock)

Borosilicate Glass (Manufactured) (SiO2 + B2O3 (Silicon dioxide and Boron trioxide)) — Synthetic/Amorphous Solid

Borosilicate Glass (Manufactured)

SiO2 + B2O3 (Silicon dioxide and Boron trioxide)

Synthetic/Amorphous Solid

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

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Carnelian Agate (Silicon Dioxide (SiO2) with Hematite inclusions) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with Hematite inclusions

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

Moss Agate

Chalcedony (Silicon Dioxide) with inclusions - SiO2

Basalt River Stone (Aphanitic Mafic Igneous Rock) — igneous

Basalt River Stone

Aphanitic Mafic Igneous Rock

Basalt with Iron Oxidation (Vesicular Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt with Iron Oxidation

Vesicular Basalt (Aphanitic Mafic Igneous Rock)

Granodiorite Pebble (Granodiorite) — igneous

Granodiorite Pebble

Granodiorite

Basalt with Weathered Rind (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt with Weathered Rind

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Mica Schist (Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)) — metamorphic

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Chert (Jasper/Quartzite river stone) (Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Quartzite river stone)

Microcrystalline Silicon Dioxide (SiO2)

Yellow Chert (Microcrystalline Quartz) (Chert / SiO2 (Silicon Dioxide)) — sedimentary

Yellow Chert (Microcrystalline Quartz)

Chert / SiO2 (Silicon Dioxide)