Rock Identifier

Category

Industrial Byproduct (Often Mistaken For Obsidian Or Mineral)

Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.

Agate (specifically a Blue Agate Geode Slice) (Chalcedony (cryptocrystalline variety of Quartz); SiO2) — mineral

Agate (specifically a Blue Agate Geode Slice)

Chalcedony (cryptocrystalline variety of Quartz); SiO2

Granodiorite (Granodiorite (Intermediate intrusive igneous rock)) — igneous

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Agate Geode (Chalcedony (SiO2 - Silicon Dioxide)) — sedimentary (secondary mineral formation)

Agate Geode

Chalcedony (SiO2 - Silicon Dioxide)

sedimentary (secondary mineral formation)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Chalcedony or Chert/Jasper with secondary mineral staining (SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.) — Mineral, potentially a rock with chalcedony/jasper.

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Mineral, potentially a rock with chalcedony/jasper.

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Rutilated Quartz (Quartz (SiO2) with Rutile inclusions (TiO2)) — Mineral

Rutilated Quartz

Quartz (SiO2) with Rutile inclusions (TiO2)

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

Marble (Metamorphosed Limestone (calcite formulation CaCO3)) — metamorphic

Marble

Metamorphosed Limestone (calcite formulation CaCO3)

Agate (Agate (Silicon Dioxide, SiO2)) — mineral

Agate

Agate (Silicon Dioxide, SiO2)

Red Sandstone (Arenite (primarily Quartz with Iron Oxide coating)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Iron Oxide coating)

Chert (Jasper variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper variety)

Microcrystalline quartz (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Coal (most likely Bituminous or Anthracite) (Coal (primarily composed of carbon with varying amounts of other elements)) — Sedimentary rock

Coal (most likely Bituminous or Anthracite)

Coal (primarily composed of carbon with varying amounts of other elements)

Sedimentary rock

Quartzite Pebble (Quartzite (primarily SiO2)) — metamorphic

Quartzite Pebble

Quartzite (primarily SiO2)

Chert (Flint) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Basalt with Mineral Vein (Cobble) (Basalt (with likely Quartz/Calcite vein)) — Igneous

Basalt with Mineral Vein (Cobble)

Basalt (with likely Quartz/Calcite vein)

Anthracite Coal (Anthracite (Carbon)) — metamorphic

Anthracite Coal

Anthracite (Carbon)

Sandstone (likely Quartzose) (Arenite (primarily SiO2)) — sedimentary

Sandstone (likely Quartzose)

Arenite (primarily SiO2)

Chalcedony (Common Opal variant) (Silicon dioxide (SiO2) with varying levels of hydration) — mineral

Chalcedony (Common Opal variant)

Silicon dioxide (SiO2) with varying levels of hydration

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Red Garnet (Pyrope or Almandine) (Garnet Group (A3B2(SiO4)3)) — mineral

Red Garnet (Pyrope or Almandine)

Garnet Group (A3B2(SiO4)3)

Diamond (in jewelry setting) (Carbon (C)) — mineral

Diamond (in jewelry setting)

Carbon (C)

Iolite (Cordierite) (Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18) — mineral

Iolite (Cordierite)

Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18

Diamond (Diamond (pure Carbon, C)) — mineral

Diamond

Diamond (pure Carbon, C)

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

Peridot

Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4

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

Clear Quartz (Druzy)

Crystalline Silicon Dioxide (SiO2)

Milky Quartz with Iron Inclusions (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

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

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Banded Agate (Chalcedony / Silicon Dioxide (SiO2)) — mineral

Banded Agate

Chalcedony / Silicon Dioxide (SiO2)

Quartz Pebble (Chalcedony/Agate) (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble (Chalcedony/Agate)

Silicon Dioxide (SiO2)

Diamond (Diamond (C)) — mineral

Diamond

Diamond (C)

Quartz Pebble (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Quartzite Pebbles (Quartzite (SiO2)) — metamorphic

Quartzite Pebbles

Quartzite (SiO2)

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

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Parti Sapphire (Corundum (Al2O3)) — mineral

Parti Sapphire

Corundum (Al2O3)

Aquamarine (Pale variety) (Beryl (Be3Al2Si6O18)) — mineral

Aquamarine (Pale variety)

Beryl (Be3Al2Si6O18)

Milky Quartz (Crystal Cluster) (Silicon Dioxide (SiO2) - Quartz Variety) — mineral

Milky Quartz (Crystal Cluster)

Silicon Dioxide (SiO2) - Quartz Variety

Rough Diamond (Pure Carbon (C)) — mineral

Rough Diamond

Pure Carbon (C)

Chalcedony (Agate/Chert variety) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO₂)

Black Tourmaline (Schorl) (Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4) — mineral

Black Tourmaline (Schorl)

Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4