Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Yellow Quartzite (Quartzite (SiO2)) — metamorphic

Yellow Quartzite

Quartzite (SiO2)

Quartz on Greenstone (Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit) — metamorphic

Quartz on Greenstone

Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Unidentifiable Rock Fragment — Uncertain

Unidentifiable Rock Fragment

Red Jasper (Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)) — sedimentary

Red Jasper

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Chrysocolla and Azurite in Matrix (Hydrated copper phyllosilicate (Chrysocolla - Cu2H2Si2O5(OH)4) and Copper carbonate (Azurite - Cu3(CO3)2(OH)2)) — mineral

Chrysocolla and Azurite in Matrix

Hydrated copper phyllosilicate (Chrysocolla - Cu2H2Si2O5(OH)4) and Copper carbonate (Azurite - Cu3(CO3)2(OH)2)

Limestone (Calcite (CaCO3)) — sedimentary

Limestone

Calcite (CaCO3)

Rough Emerald in Matrix (Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium) — mineral

Rough Emerald in Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

Granite (Granite (Felsic Plutonic Rock)) — Igneous

Granite

Granite (Felsic Plutonic Rock)

Amethyst Quartz Druse (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst Quartz Druse

Silicon Dioxide (SiO2) with iron impurities

Granite (with alteration) (Granite (Felsic intrusive igneous rock)) — igneous

Granite (with alteration)

Granite (Felsic intrusive igneous rock)

Granite (Background) and Quartzite/River Pebble (Foreground Heart) (Phaneritic Felsic Igneous Rock (Granite background)) — igneous

Granite (Background) and Quartzite/River Pebble (Foreground Heart)

Phaneritic Felsic Igneous Rock (Granite background)

Desert Varnish (on Sandstone) (Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)) — sedimentary

Desert Varnish (on Sandstone)

Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)

Blue Lace Agate (Chalcedony (SiO2) with trace inclusions) — mineral

Blue Lace Agate

Chalcedony (SiO2) with trace inclusions

Yellow Quartzite (River Pebble) (Quartzite (primarily Silicon Dioxide, SiO2)) — metamorphic

Yellow Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide, SiO2)

Amethyst (Faceted) (Amethyst (Silicon Dioxide with iron impurities, SiO2)) — mineral

Amethyst (Faceted)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Glauconite (Glauconitic Sandstone) (Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]) — sedimentary

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Limestone (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Massive Quartz with Host Rock (Silicon Dioxide (SiO2)) — mineral

Massive Quartz with Host Rock

Silicon Dioxide (SiO2)

Fossiliferous Limestone (Limestone (composed primarily of calcite with included fossils CaCO3)) — Sedimentary

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Granite (Granite (a plutonic igneous rock)) — Igneous

Granite

Granite (a plutonic igneous rock)

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

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Banded Gneiss (River Rock/Pebble) (Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)) — Metamorphic Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Metamorphic Rock

Desert Rose (Gypsum (variety Selenite) or Barite, CaSO4·2H2O) — mineral

Desert Rose

Gypsum (variety Selenite) or Barite, CaSO4·2H2O

Coquina (Coquina (Bioclastic Limestone)) — sedimentary

Coquina

Coquina (Bioclastic Limestone)

Granite (Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)

Granite (Phaneritic plutonic rock (Felsic)) — igneous

Granite

Phaneritic plutonic rock (Felsic)

Granite (Granite (Phaneritic igneous rock)) — igneous

Granite

Granite (Phaneritic igneous rock)

Porphyry (Porphyritic Rhyolite or Andesite) — igneous

Porphyry

Porphyritic Rhyolite or Andesite

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

River Stone / Pebble (Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)) — Mineral, Sediment

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Mineral, Sediment

Fossilized Coral (Petoskey-like or Favosites) (Anthozoa (Fossilized Coral)) — sedimentary

Fossilized Coral (Petoskey-like or Favosites)

Anthozoa (Fossilized Coral)

Dendritic Opal (Common Opal) (Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions) — mineral

Dendritic Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions

Septarian Nodule (Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)) — sedimentary

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)

Chert (Hag Stone / Hole Stone) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Hag Stone / Hole Stone)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Rhyolitic Tuff (Breccia Type) (Rhyolitic Pyroclastic Rock (Mixed Silicates including Quartz, Feldspar, and Volcanic Glass)) — igneous

Rhyolitic Tuff (Breccia Type)

Rhyolitic Pyroclastic Rock (Mixed Silicates including Quartz, Feldspar, and Volcanic Glass)

Banded Rock (likely Quartz-rich) (Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals) — Mineral

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Pegmatite (Granitic Pegmatite) — igneous

Pegmatite

Granitic Pegmatite

Granite Pebble (Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite Pebble

Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)