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.

Red Siltstone (or Red Shale) (Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)) — sedimentary

Red Siltstone (or Red Shale)

Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)

Sandstone (Tumbled/River Pebble) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (Tumbled/River Pebble)

Arenite (composed primarily of SiO2)

Quartz Druzy Geode (Silicon Dioxide (SiO2) - Crystalline Variety) — mineral

Quartz Druzy Geode

Silicon Dioxide (SiO2) - Crystalline Variety

Feldspar (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8) — mineral

Feldspar

KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8

Limonite (after Pyrite Pseudomorph) (Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)) — mineral

Limonite (after Pyrite Pseudomorph)

Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)

Quartz Geode Fragment (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Chert (Polished Gemstone / River Stone) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Polished Gemstone / River Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (and/or Flint)

Microcrystalline Quartz (SiO2)

Shale (Argillaceous Rock) — sedimentary

Shale

Argillaceous Rock

Gneiss (Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)) — metamorphic

Gneiss

Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)

Amazonite (Potassium aluminum silicate (KAlSi3O8)) — mineral

Amazonite

Potassium aluminum silicate (KAlSi3O8)

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

Rough Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — mineral

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Botryoidal Chalcedony (Silicon Dioxide (SiO2)) — mineral

Botryoidal Chalcedony

Silicon Dioxide (SiO2)

Quartz (Smoky Quartz variant) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Amethyst (Quartz variety) (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst (Quartz variety)

Silicon Dioxide (SiO2) with iron impurities

Alexandrite (Chrysoberyl (BeAl2O4 with Chromium impurities)) — mineral

Alexandrite

Chrysoberyl (BeAl2O4 with Chromium impurities)

Emerald (Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium) — mineral

Emerald

Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium

Amethyst (Raw Quartz) (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst (Raw Quartz)

Silicon Dioxide (SiO2) with iron impurities

Amethyst (Silicon dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon dioxide (SiO2) with iron impurities

Sunstone (Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)) — mineral

Sunstone

Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)

Sandstone (Pebble/Cobble) (Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)) — Sedimentary

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Sandstone (Wonderstone) (Arenite (composed primarily of SiO2 with Fe2O3 impurities)) — sedimentary

Sandstone (Wonderstone)

Arenite (composed primarily of SiO2 with Fe2O3 impurities)

Sandstone (with Iron Staining) (Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)

Sandstone (Banded Sandstone) (Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)) — sedimentary

Sandstone (Banded Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)

Chert (with Limestone/Dolomite host) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Limestone/Dolomite host)

Microcrystalline Quartz (SiO2)

Moqui Marble (Shaman Stone) (Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)) — sedimentary

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Shale (Fissile Siliciclastic Sedimentary Rock) — sedimentary

Shale

Fissile Siliciclastic Sedimentary Rock

Chert (and Petrified Wood) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Petrified Wood)

Silicon Dioxide (SiO2)

Quartz (Druzy) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy)

Silicon Dioxide (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Gneiss (with Quartzite and Biotite) (Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)) — metamorphic

Gneiss (with Quartzite and Biotite)

Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)

Pearl (Imitation or Cultured) (Calcium Carbonate (Aragonite/Calcite) - CaCO3) — Mineraloid (Organic)

Pearl (Imitation or Cultured)

Calcium Carbonate (Aragonite/Calcite) - CaCO3

Mineraloid (Organic)

Amphibolite (Amphibolite) — metamorphic

Amphibolite

Amphibolite

Agate Geode (Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety) — Mineral

Agate Geode

Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety

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

Chert (White Chert)

Silicon Dioxide (SiO2)

Porphyritic Basalt (with Pyrolusite or Iron-oxide staining) (Porphyritic Basalt (Mafic Extrusive)) — igneous

Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)

Porphyritic Basalt (Mafic Extrusive)

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

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Chert (Yellow or Tan Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow or Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint in this variation) (Silicon dioxide (SiO2) - Microcrystalline quartz) — sedimentary

Chert (often called Flint in this variation)

Silicon dioxide (SiO2) - Microcrystalline quartz