Rock Identifier

Category

Rock

Browse rock specimens identified by the Rock Identifier community.

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

sedimentary
United States Quarter Dollar (Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)) — Metal / Man-made mineral-like object

United States Quarter Dollar

Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)

Metal / Man-made mineral-like object
Quartz Pebble (Iron-stained) (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

mineral
Red Jasper (Heliotrope family variant) (Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)) — sedimentary

Red Jasper (Heliotrope family variant)

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

sedimentary
Quartz Pebble (Geode-like) (Silicon Dioxide (SiO2)) — Mineral

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Mineral
Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

mineral
Pink Granite (Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)) — igneous

Pink Granite

Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)

igneous
Limonite-stained Quartz / Quartzite (Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)) — sedimentary or metamorphic

Limonite-stained Quartz / Quartzite

Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)

sedimentary or metamorphic
Quartz (Vein Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

mineral
Travertine (Tufa) (Chemical Sedimentary Limestone (CaCO3)) — sedimentary

Travertine (Tufa)

Chemical Sedimentary Limestone (CaCO3)

sedimentary
Sandstone (Sandstone (clastic sedimentary rock, predominantly SiO2)) — sedimentary

Sandstone

Sandstone (clastic sedimentary rock, predominantly SiO2)

sedimentary
River Cobble (Quartzite with Iron Staining) (Metamorphic Quartzite (SiO2 with Fe2O3 inclusions)) — metamorphic

River Cobble (Quartzite with Iron Staining)

Metamorphic Quartzite (SiO2 with Fe2O3 inclusions)

metamorphic
Tufa (Calcareous Tufa (CaCO3)) — sedimentary

Tufa

Calcareous Tufa (CaCO3)

sedimentary
Granite River Pebble (Phaneritic Felsic Igneous Rock (Granite)) — igneous

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

igneous
Granite (Granite (Felsic Intrusive Igneous Rock)) — igneous

Granite

Granite (Felsic Intrusive Igneous Rock)

igneous
Granodiorite (Granodiorite (phaneritic intrusive igneous rock)) — igneous

Granodiorite

Granodiorite (phaneritic intrusive igneous rock)

igneous
Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

igneous
Porphyritic Andesite (Andesite (Intermediate Extrusive Volcanic Rock)) — igneous

Porphyritic Andesite

Andesite (Intermediate Extrusive Volcanic Rock)

igneous
Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

igneous
Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

igneous
Basalt (River Pebble) (Basalt (Aphanitic Mafic Volcanic Rock)) — Igneous

Basalt (River Pebble)

Basalt (Aphanitic Mafic Volcanic Rock)

Igneous
Limonite (Iron-rich Siltstone / Sandstone base) (Hydrous ferric oxide mixture (FeO(OH)·nH2O)) — sedimentary

Limonite (Iron-rich Siltstone / Sandstone base)

Hydrous ferric oxide mixture (FeO(OH)·nH2O)

sedimentary
Milky Quartz (Quartz / Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

mineral
Chalcedony (Grey/White Agate) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Grey/White Agate)

Silicon Dioxide (SiO₂)

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

Smoky Quartz

Silicon Dioxide (SiO2)

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

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Mineral
Labradorite ((Ca, Na)(Al, Si)4O8) — mineral

Labradorite

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

mineral
Yellow Quartz (Citrine or Yellow Jasper) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine or Yellow Jasper)

Silicon Dioxide (SiO2)

mineral
Geode (Chert or Quartz Nodule) (Silicon Dioxide (SiO2)) — sedimentary

Geode (Chert or Quartz Nodule)

Silicon Dioxide (SiO2)

sedimentary
Muscovite Mica (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

mineral
Porphyritic Basalt (Chinese Writing Stone or Flower Stone) (Porphyritic Basalt / Porphyry) — igneous

Porphyritic Basalt (Chinese Writing Stone or Flower Stone)

Porphyritic Basalt / Porphyry

igneous
Diorite (Intrusive Igneous Rock (Intermediate Composition)) — igneous

Diorite

Intrusive Igneous Rock (Intermediate Composition)

igneous
Pumice (Pumice (a highly vesicular volcanic rock)) — igneous

Pumice

Pumice (a highly vesicular volcanic rock)

igneous
Dalmatian Stone (commonly Dyed) (Dalmatian Jasper (Peralkaline igneous rock)) — igneous

Dalmatian Stone (commonly Dyed)

Dalmatian Jasper (Peralkaline igneous rock)

igneous
Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

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

Gneiss

Gneiss (High-grade metamorphic rock)

metamorphic
Granite (Granite (Felsic intrusive igneous rock)) — igneous

Granite

Granite (Felsic intrusive igneous rock)

igneous
Crushed Stone (Likely Granite or Diabase) (Intrusive Igneous Rock (Granitoid/Gabbroid)) — igneous

Crushed Stone (Likely Granite or Diabase)

Intrusive Igneous Rock (Granitoid/Gabbroid)

igneous
Basalt (River Stone) (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt (River Stone)

Basalt (Mafic Extrusive Igneous Rock)

igneous
Pink Feldspar (Orthoclase Feldspar (KAlSi3O8)) — mineral

Pink Feldspar

Orthoclase Feldspar (KAlSi3O8)

mineral
Orthoclase Feldspar (Orthoclase (KAlSi3O8)) — mineral

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

mineral
Basalt (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

igneous