Rock Identifier

Category

Organic Gemstone (Not A Rock Or Mineral)

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

Chert (specifically Flint or Gray Chert) (Silicon Dioxide (Microcrystalline Quartz), SiO2) — sedimentary

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (Microcrystalline Quartz), SiO2

River Rock (likely Siltstone or fine-grained Sandstone) (Clastic Sedimentary Rock) — sedimentary

River Rock (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock

Sandstone (Sandstone (Sedimentary rock composed of silicate grains)) — sedimentary

Sandstone

Sandstone (Sedimentary rock composed of silicate grains)

Sandstone (with Lichen) (Arenite (primarily SiO2)) — sedimentary

Sandstone (with Lichen)

Arenite (primarily SiO2)

Note regarding image quality — Indeterminate

Note regarding image quality

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Potassium Feldspar (Orthoclase) (Orthoclase (KAlSi3O8)) — mineral

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

Quartz (Rock Crystal) with minor impurities (Quartz (SiO2)) — Mineral

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Serpentine (Antigorite, Lizardite, or Chrysotile (Mg,Fe)3Si2O5(OH)4) — metamorphic

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg,Fe)3Si2O5(OH)4

Gold-Bearing Quartz (Silicon Dioxide with Native Gold (SiO2 + Au)) — mineral

Gold-Bearing Quartz

Silicon Dioxide with Native Gold (SiO2 + Au)

Chert (often called Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz (River Pebble) (Silicon Dioxide (SiO2)) — mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartz in Basalt (Xenocryst) (Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock) — Igneous

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Chert (variant Flint/Jasper) (Microcrystalline Opaline Silica (SiO2)) — sedimentary

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

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

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Quartz Vein in Schist (Quartz (SiO2) in Mica Schist) — metamorphic

Quartz Vein in Schist

Quartz (SiO2) in Mica Schist

Quartz-veined Basalt (Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein) — igneous

Quartz-veined Basalt

Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein

Coal (most likely Bituminous or Anthracite) (Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)) — Sedimentary Rock

Coal (most likely Bituminous or Anthracite)

Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)

Sedimentary Rock

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

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Prehnite (Prehnite (Ca2Al(AlSi3O10)(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Orange Quartzite (River Pebble) (Quartzite (SiO2 with Iron Oxide inclusions)) — metamorphic

Orange Quartzite (River Pebble)

Quartzite (SiO2 with Iron Oxide inclusions)

Limonite (Iron Ore) (Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)

Quartz (Silicon dioxide (SiO2)) — Mineral

Quartz

Silicon dioxide (SiO2)

Basalt with Quartz Veining (Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins) — igneous

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Quartz-Veined Mudstone (Argillaceous Mudstone with Quartz Veining) — sedimentary

Quartz-Veined Mudstone

Argillaceous Mudstone with Quartz Veining

Citrine Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Citrine (Silicon Dioxide (SiO2)) — mineral

Citrine

Silicon Dioxide (SiO2)

Granite (Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite

Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)

Garnet Beads (Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)) — Mineral

Garnet Beads

Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)

Clear Quartz (Silicon dioxide (SiO2)) — mineral

Clear Quartz

Silicon dioxide (SiO2)

Lapis Lazuli (Tumbled) (Lazurite-dominated contact metamorphic rock) — metamorphic

Lapis Lazuli (Tumbled)

Lazurite-dominated contact metamorphic rock

Lapis Lazuli (Na8[Al6Si6O24]Sn (Lazurite-rich metamorphic rock)) — metamorphic

Lapis Lazuli

Na8[Al6Si6O24]Sn (Lazurite-rich metamorphic rock)

Tiger's Eye (with Blue Tiger's Eye / Hawk's Eye) (Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)) — metamorphic

Tiger's Eye (with Blue Tiger's Eye / Hawk's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Chert (and Jasper/Flint variant) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Chert (Flint) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Quartz (variety of colors) (SiO2 (Silicon Dioxide)) — Mineral

Quartz (variety of colors)

SiO2 (Silicon Dioxide)

Eclogite (Eclogite (Omphacite + Pyrope)) — metamorphic

Eclogite

Eclogite (Omphacite + Pyrope)

Green Apatite on Albite (Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]) — mineral

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

Cat's Eye Moonstone (Feldspar) (Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8) inclusions) — mineral

Cat's Eye Moonstone (Feldspar)

Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8) inclusions

Quartz Geode (with possible Manganese or Goethite coating) (Silicon Dioxide (SiO2)) — mineral

Quartz Geode (with possible Manganese or Goethite coating)

Silicon Dioxide (SiO2)

Bauxite (Bauxite (Al2O3·nH2O)) — sedimentary

Bauxite

Bauxite (Al2O3·nH2O)