Rock Identifier

Category

Man Made Object (Coin)

Browse man made object (coin) specimens identified by the Rock Identifier community.

Quartz (Clear Quartz/Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

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

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous) (Arenite (Fe2O3 enriched)) — sedimentary

Sandstone (Ferruginous)

Arenite (Fe2O3 enriched)

Slag (Industrial Glass) (Anthropogenic Amorphous Vitreous Silicate) — mineraloid

Slag (Industrial Glass)

Anthropogenic Amorphous Vitreous Silicate

Black Sapphire (Corundum (Al2O3 with iron and titanium impurities)) — mineral

Black Sapphire

Corundum (Al2O3 with iron and titanium impurities)

Cobaltian Calcite (Cobaltoan Calcite) (Cobalt-bearing Calcite (Ca,Co)CO3) — mineral

Cobaltian Calcite (Cobaltoan Calcite)

Cobalt-bearing Calcite (Ca,Co)CO3

Red Scoria (Lava Rock) (Scoria (Extrusive Igneous Rock / Mafic composition)) — igneous

Red Scoria (Lava Rock)

Scoria (Extrusive Igneous Rock / Mafic composition)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Druzy Quartz on Vesicular Basalt (Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock) — igneous

Druzy Quartz on Vesicular Basalt

Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock

Fossil Shell Fragment (possibly Brachiopod or Bivalve) (Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca) — sedimentary

Fossil Shell Fragment (possibly Brachiopod or Bivalve)

Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Red Sandstone (Arenite (primarily Quartz with Hematite cement)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Green Fluorite (Beaded) (Fluorite (Calcium Fluoride, CaF2)) — mineral

Green Fluorite (Beaded)

Fluorite (Calcium Fluoride, CaF2)

Golden Quartz (Citrine or Iron-stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Golden Quartz (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Vesicular Basalt (Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)) — igneous

Vesicular Basalt

Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)

Travertine (Calcareous Tufa / Travertine (CaCO3)) — sedimentary

Travertine

Calcareous Tufa / Travertine (CaCO3)

Red Jasper (Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)) — sedimentary

Red Jasper

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

Garnet (likely Almandine, Pyrope, or a blend) (Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)) — Mineral

Garnet (likely Almandine, Pyrope, or a blend)

Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)

Granite (Granite (Mainly Quartz, Feldspar, and Mica)) — igneous

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Sandstone (Wonderstone) (Silicified Sandstone / Orthoquartzite with Liesegang rings) — sedimentary

Sandstone (Wonderstone)

Silicified Sandstone / Orthoquartzite with Liesegang rings

Chert (Lake Superior Agate variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Lake Superior Agate variant)

Microcrystalline Quartz (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Slate (Slate (Metamorphosed Mudstone/Shale)) — metamorphic

Slate

Slate (Metamorphosed Mudstone/Shale)

Red Sandstone (Arenite (primarily Quartz with Hematite cement)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Green Agate (Silicon Dioxide (SiO2) - Chalcedony variety) — mineral

Green Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Sandstone (Red) (Arenite (primarily SiO2 with Iron Oxide staining)) — sedimentary

Sandstone (Red)

Arenite (primarily SiO2 with Iron Oxide staining)

Pink Quartzite (Quartzite (mainly SiO2 with iron oxide impurities)) — metamorphic

Pink Quartzite

Quartzite (mainly SiO2 with iron oxide impurities)

Jasper (Jasper (Silicate mineral, SiO2)) — sedimentary

Jasper

Jasper (Silicate mineral, SiO2)

Ferruginous Sandstone (Ironstone) (Sedimentary rock with Limonite/Goethite cement) — sedimentary

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

Chert (Flint) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Diamond (Carbon (C)) — Mineral

Diamond

Carbon (C)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Slate (Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)) — metamorphic

Slate

Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)

Fluorite (Rainbow/Purple Fluorite) (Calcium Fluoride (CaF2)) — mineral

Fluorite (Rainbow/Purple Fluorite)

Calcium Fluoride (CaF2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Basalt (Basalt (Mafic igneous rock)) — igneous

Basalt

Basalt (Mafic igneous rock)

Sandstone (with potential mineral staining/concretions) (Arenite (SiO2 based)) — sedimentary

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Red Jasper (Silicon Dioxide (SiO2) with Iron impurities) — mineral

Red Jasper

Silicon Dioxide (SiO2) with Iron impurities

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)