Rock Identifier

Category

Man Made Object (Coin)

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

Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)) — igneous

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Basalt (Extrusive Mafic Igneous Rock (composed primarily of Plagioclase, Pyroxene, and Olivine)) — igneous

Basalt

Extrusive Mafic Igneous Rock (composed primarily of Plagioclase, Pyroxene, and Olivine)

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Granite (weathered/river-tumbled) (Granite (Plutonic Igneous Rock)) — Igneous Rock

Granite (weathered/river-tumbled)

Granite (Plutonic Igneous Rock)

Sandstone (Sandstone (lithified arenite/wacke)) — Sedimentary Rock

Sandstone

Sandstone (lithified arenite/wacke)

Sedimentary Rock

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)

Moonstone (Orthoclase Feldspar (KAlSi3O8)) — Mineral

Moonstone

Orthoclase Feldspar (KAlSi3O8)

Crazy Lace Agate (Silicon Dioxide (SiO2) with iron and aluminum inclusions) — sedimentary mineral

Crazy Lace Agate

Silicon Dioxide (SiO2) with iron and aluminum inclusions

sedimentary mineral

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Mookaite Jasper (Silicified Radiolarite (SiO2 with impurities)) — sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2 with impurities)

Fluorite (likely) (Calcium Fluoride (CaF2)) — Mineral

Fluorite (likely)

Calcium Fluoride (CaF2)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Citrine Geode (or Druzy Citrine) (Silicon Dioxide (SiO₂) - a variety of Quartz) — Mineral

Citrine Geode (or Druzy Citrine)

Silicon Dioxide (SiO₂) - a variety of Quartz

Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Gneiss

Gneiss (High-grade metamorphic rock)

Granite with Mafic Inclusions (Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)) — igneous

Granite with Mafic Inclusions

Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)

Peridot (Olivine ((Mg,Fe)2SiO4)) — Mineral

Peridot

Olivine ((Mg,Fe)2SiO4)

Pegmatite with Schorl (Black Tourmaline) and Mica (Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)) — igneous

Pegmatite with Schorl (Black Tourmaline) and Mica

Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)

Geode (Unopened) (Silica-rich Concretion (primarily SiO2)) — sedimentary

Geode (Unopened)

Silica-rich Concretion (primarily SiO2)

Crushed Limestone and Calcite (Calcium Carbonate (CaCO3)) — sedimentary

Crushed Limestone and Calcite

Calcium Carbonate (CaCO3)

Red Jasper (Silicon Dioxide (SiO2) with Hematite inclusions) — mineral

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Pink Granite (Phaneritic Felsic Igneous Plutonic Rock) — igneous

Pink Granite

Phaneritic Felsic Igneous Plutonic Rock

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)) — metamorphic

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Rose Quartz (Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron

Moonstone (specifically White Moonstone or Girasol Quartz) (Potassium aluminum silicate (KAlSi3O8)) — mineral

Moonstone (specifically White Moonstone or Girasol Quartz)

Potassium aluminum silicate (KAlSi3O8)

Basalt (Basalt (composition predominately plagioclase feldspar and pyroxene)) — igneous

Basalt

Basalt (composition predominately plagioclase feldspar and pyroxene)

Sandstone (likely Ferruginous) (Sandstone (SiO2 with iron oxides)) — sedimentary

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Quartz (Silicon Dioxide (SiO2)) — Mineral

Quartz

Silicon Dioxide (SiO2)

Ruby (Corundum (Al₂O₃) with Chromium (Cr)) — Mineral (gemstone)

Ruby

Corundum (Al₂O₃) with Chromium (Cr)

Mineral (gemstone)

Sandstone (Sandstone (clastic sedimentary rock)) — Rock

Sandstone

Sandstone (clastic sedimentary rock)

Banded Gneiss (Gneiss (pronounced 'nice')) — metamorphic

Banded Gneiss

Gneiss (pronounced 'nice')

Pyrite (Pyrite (FeS2)) — Mineral

Pyrite

Pyrite (FeS2)

Quartz (likely milky quartz or a stained variety) (Silicon Dioxide (SiO₂)) — Mineral

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

Schist (Schist (various mineral compositions)) — Metamorphic

Schist

Schist (various mineral compositions)

Nephrite Jade (Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)) — metamorphic

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Banded Gneiss (Gneiss (variable mineral composition)) — metamorphic

Banded Gneiss

Gneiss (variable mineral composition)

Fossil Coral (Coral Limestone (a type of biogenic sedimentary rock)) — Sedimentary

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Labradorite (likely Black Labradorite or Larvikite) (Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.) — Mineral/Igneous Rock

Labradorite (likely Black Labradorite or Larvikite)

Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.

Mineral/Igneous Rock

Quartz (chalcedony variety) or Limestone with Quartz Veins (SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)) — Mineral or Sedimentary Rock (with mineral inclusions)

Quartz (chalcedony variety) or Limestone with Quartz Veins

SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)

Mineral or Sedimentary Rock (with mineral inclusions)

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)

Diorite (Spotted or Dalmatian Stone pattern) (Diorite) — igneous

Diorite (Spotted or Dalmatian Stone pattern)

Diorite

Chert (Common Opal/Agate inclusion) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Common Opal/Agate inclusion)

Microcrystalline Quartz (SiO2)