Rock Identifier

Category

Mineralological Specimen

Browse mineralological specimen specimens identified by the Rock Identifier community.

Sandstone with Secondary Mineral Encrustation (Arenite with Silica/Calcite deposits (SiO2 or CaCO3)) — sedimentary

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Chert (Arrowhead/Tool variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

Chalcedony (Agate/Jasper mix in host rock) (Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)) — mineral

Chalcedony (Agate/Jasper mix in host rock)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Pink Anthracite Coal (dyed) (Anthracite Coal (Artificially Colored)) — Sedimentary Rock (Altered)

Pink Anthracite Coal (dyed)

Anthracite Coal (Artificially Colored)

Sedimentary Rock (Altered)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Chalcanthite (Likely Synthetic/Lab-Grown) (Hydrated copper(II) sulfate (CuSO4·5H2O)) — mineral

Chalcanthite (Likely Synthetic/Lab-Grown)

Hydrated copper(II) sulfate (CuSO4·5H2O)

Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx') (Calcium Carbonate (CaCO3)) — sedimentary

Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')

Calcium Carbonate (CaCO3)

Quartz (Double-Terminated) (Silicon Dioxide (SiO2)) — mineral

Quartz (Double-Terminated)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Amazonite (Potassium Feldspar (KAlSi3O8), specifically Microcline) — mineral

Amazonite

Potassium Feldspar (KAlSi3O8), specifically Microcline

Fossiliferous Limestone with Rugose Coral (Rugosa (order), typically preserved in CaCO3 (Calcite)) — sedimentary

Fossiliferous Limestone with Rugose Coral

Rugosa (order), typically preserved in CaCO3 (Calcite)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Red Quartzite / Metasandstone River Pebble (Quartzite (primarily SiO2 with hematite inclusions)) — metamorphic

Red Quartzite / Metasandstone River Pebble

Quartzite (primarily SiO2 with hematite inclusions)

Quartzite (or Quartz Rich Conglomerate) (Quartzite (SiO2 silicon dioxide)) — metamorphic

Quartzite (or Quartz Rich Conglomerate)

Quartzite (SiO2 silicon dioxide)

Ferruginous Conglomerate (or Iron-Rich Concrete/Slag) (Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)) — sedimentary

Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)

Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt) — igneous

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Sandstone (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone

Arenite (composed primarily of SiO2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Smoky Quartz (Chlorite Inclusions) (Silicon Dioxide (SiO2) with trace Aluminum and Natural Irradiation) — mineral

Smoky Quartz (Chlorite Inclusions)

Silicon Dioxide (SiO2) with trace Aluminum and Natural Irradiation

Blue Agate (Tumbled and Dyed) (Silicon Dioxide (SiO2) with likely organic dyes) — mineral

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Clear Quartz (Herkimer Diamond variant) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Herkimer Diamond variant)

Silicon Dioxide (SiO2)

Rough Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rough Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Black Tourmaline (Schorl) (Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))) — mineral

Black Tourmaline (Schorl)

Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))

Glauconitic Sandstone (Greensand pebble) (Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (Greensand pebble)

Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)

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

Granite Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite) (Calcium Fluoride (CaF2)) — mineral

Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite)

Calcium Fluoride (CaF2)

Brown Jasper (Jasper (a cryptocrystalline variety of Quartz, SiO2)) — Mineral, specifically a variety of Quartz

Brown Jasper

Jasper (a cryptocrystalline variety of Quartz, SiO2)

Mineral, specifically a variety of Quartz

Yellow Quartz (Citrine-colored Quartz Pebble) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine-colored Quartz Pebble)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood) (Silicified Wood (primarily Chalcedony/Quartz, SiO2)) — mineral

Petrified Wood (Silicified Wood)

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

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

Sandstone (Quartzose)

Arenite (primarily SiO2)

Ferruginous Quartz (Red Quartz) (Silicon Dioxide (SiO2) with Hematite/Limonite impurities) — mineral

Ferruginous Quartz (Red Quartz)

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Kunzite (Spodumene (LiAlSi2O6)) — mineral

Kunzite

Spodumene (LiAlSi2O6)

Druzy Agate (specifically Black Druzy Agate) (Silicon Dioxide (SiO2)) — mineral

Druzy Agate (specifically Black Druzy Agate)

Silicon Dioxide (SiO2)

Yellow Quartzite (Onyx Pebble) (Silicon Dioxide (SiO2) - Quartzite) — metamorphic

Yellow Quartzite (Onyx Pebble)

Silicon Dioxide (SiO2) - Quartzite

Yellow Quartz Pebble (Citrine or Iron-Stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz Pebble (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Blue Calcite (Calcium Carbonate (CaCO3)) — mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Conglomerate (or Breccia) (Clastic Sedimentary Rock (Conglomeratic)) — sedimentary

Conglomerate (or Breccia)

Clastic Sedimentary Rock (Conglomeratic)

Basalt Cobble (Vesicular Basalt (Mafic Extrusive)) — igneous

Basalt Cobble

Vesicular Basalt (Mafic Extrusive)

Chert (varietal: Flint/River Pebble) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (varietal: Flint/River Pebble)

Cryptocrystalline Quartz (SiO2)

Jasper (River pebble) (Jasper / Silicon Dioxide (SiO2)) — sedimentary

Jasper (River pebble)

Jasper / Silicon Dioxide (SiO2)