Rock Identifier

Category

Not A Natural Rock

Browse not a natural rock specimens identified by the Rock Identifier community.

Learn about Not A Natural Rock in the encyclopedia

Asphalt Rock

Rock Gypsum

Coral Rock

Rock Salt

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Chalk

Obsidian

Baddeleyite

Cataclasite

Anorthosite

Kimberlite

Granite (Granite (composed of Quartz, Felspar, and Mica)) — igneous

Granite

Granite (composed of Quartz, Felspar, and Mica)

Citrine (Silicon Dioxide (SiO2) with trace Iron) — mineral

Citrine

Silicon Dioxide (SiO2) with trace Iron

Smooth gray river pebble (Likely fine-grained sandstone or siltstone; exact identification requires a fresh surface and tests) — sedimentary

Smooth gray river pebble

Likely fine-grained sandstone or siltstone; exact identification requires a fresh surface and tests

Dalmatian jasper (Orbicular microcrystalline quartz rock, commonly rhyolitic or volcanic-feldspar matrix with black arfvedsonite/alkali-amphibole inclusions) — igneous

Dalmatian jasper

Orbicular microcrystalline quartz rock, commonly rhyolitic or volcanic-feldspar matrix with black arfvedsonite/alkali-amphibole inclusions

Granite (Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase Feldspar)) — igneous

Granite

Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase Feldspar)

Amethyst (Amethyst (SiO2)) — mineral

Amethyst

Amethyst (SiO2)

Red Sandstone (Quartzose Sandstone (SiO2)) — sedimentary

Red Sandstone

Quartzose Sandstone (SiO2)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Amethyst (Amethyst (Silica mineral, SiO2)) — mineral

Amethyst

Amethyst (Silica mineral, SiO2)

Sandstone (Sedimentary Rock (Quartz Sandstone)) — sedimentary

Sandstone

Sedimentary Rock (Quartz Sandstone)

Weathered granite or granitic gneiss (Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss) — igneous

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss

Mica Schist (Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)) — metamorphic

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Red jasper-like chalcedony pebble (Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper) — mineral

Red jasper-like chalcedony pebble

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Tumbled Stones (various) (Mixed Silica-based Minerals (primarily Quartz and Chalcedony)) — mineral

Tumbled Stones (various)

Mixed Silica-based Minerals (primarily Quartz and Chalcedony)

Blue Lace Agate (Cryptocrystalline Quartz (SiO2) with trace minerals) — sedimentary

Blue Lace Agate

Cryptocrystalline Quartz (SiO2) with trace minerals

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Amethyst (Crystalline Quartz (SiO2 with iron impurities)) — gemstone

Amethyst

Crystalline Quartz (SiO2 with iron impurities)

Dyed Blue Agate (Silicon Dioxide (SiO2) with artificial pigment) — mineral

Dyed Blue Agate

Silicon Dioxide (SiO2) with artificial pigment

Pickled Dragon Eggs (Fictional Interpretation: Purple Agate or Amethyst Geodes) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Pickled Dragon Eggs (Fictional Interpretation: Purple Agate or Amethyst Geodes)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Mixed rock and mineral gravel (Predominantly granite/granodiorite, basaltic rocks, quartz, and possible gneiss; exact identification is uncertain from the image) — igneous

Mixed rock and mineral gravel

Predominantly granite/granodiorite, basaltic rocks, quartz, and possible gneiss; exact identification is uncertain from the image

Banded Gneiss River Pebble (Gneiss) — metamorphic

Banded Gneiss River Pebble

Gneiss

Tumbled quartz-rich stone, possibly blue quartz or granite (Quartz (SiO₂), with probable feldspar and dark accessory minerals) — mineral

Tumbled quartz-rich stone, possibly blue quartz or granite

Quartz (SiO₂), with probable feldspar and dark accessory minerals

Grey Granite (Phaneritic Felsic Intrusive Igneous Rock) — igneous

Grey Granite

Phaneritic Felsic Intrusive Igneous Rock

Carnelian Beads (Silicon Dioxide (Variety of Chalcedony), $SiO_2$) — gemstone

Carnelian Beads

Silicon Dioxide (Variety of Chalcedony), $SiO_2$

Diorite (Intermediate Phaneritic Igneous Rock (Diorite)) — igneous

Diorite

Intermediate Phaneritic Igneous Rock (Diorite)

Pink Dyed Agate (Silicon Dioxide (SiO2) - Variety Agate) — mineral

Pink Dyed Agate

Silicon Dioxide (SiO2) - Variety Agate

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Sapphire (Corundum (Al2O3)) — mineral

Sapphire

Corundum (Al2O3)

Opalite (Synthetic Opalized Glass) — gemstone

Opalite

Synthetic Opalized Glass

Gneiss (Gneiss (foliated metamorphic rock)) — metamorphic

Gneiss

Gneiss (foliated metamorphic rock)

Shale (with Iron Oxide staining) (Fissile Mudstone (primarily Quartz and Clay minerals)) — sedimentary

Shale (with Iron Oxide staining)

Fissile Mudstone (primarily Quartz and Clay minerals)

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

Amethyst

Silicon Dioxide with iron impurities (SiO2)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Black Granite (Phaneritic Mafic Igneous Rock (likely Gabbronorite or Dolerite)) — igneous

Black Granite

Phaneritic Mafic Igneous Rock (likely Gabbronorite or Dolerite)

Tumbled porphyritic granite (Granite, primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende) — igneous

Tumbled porphyritic granite

Granite, primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Green Aventurine (Silicon Dioxide (Quartz) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)) — metamorphic

Green Aventurine

Silicon Dioxide (Quartz) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)

Banded Agate (Microcrystalline Quartz (SiO2) with impurities) — mineral

Banded Agate

Microcrystalline Quartz (SiO2) with impurities

Sandstone (Sedimentary Rock) (Arenite (SiO2 based)) — sedimentary

Sandstone (Sedimentary Rock)

Arenite (SiO2 based)

Opalite (Synthetic Opalite (Man-made glass)) — mineral

Opalite

Synthetic Opalite (Man-made glass)

Likely basaltic rock fragment (Fine-grained mafic igneous rock, probably basalt (plagioclase–pyroxene ± olivine)) — igneous

Likely basaltic rock fragment

Fine-grained mafic igneous rock, probably basalt (plagioclase–pyroxene ± olivine)