Coal
Coal (Sedimentary Rock / Organic Rock)
sedimentary
Category
Non Geological
Browse non geological specimens identified by the Rock Identifier community.
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Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (SiO2)
igneous
Quartzite (Orthoquartzite)
Quartzite (SiO2)
metamorphic
Yellow Quartzite River Cobble
Meta-quartzite (SiO2 with iron oxide staining)
metamorphic
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
sedimentary
Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO2)
metamorphic
Polished dark pebble, likely basalt
Basalt, chiefly plagioclase feldspar and pyroxene, with possible olivine or magnetite
igneous
Weathered dark flint (chert) pebble
Microcrystalline quartz (SiO₂), commonly called flint or chert
sedimentary
Quartzite
Metamorphic Quartzite
metamorphic
Tektite (Indochinite)
Tektite (Amorphous silica glass, SiO2 with impurities)
meteorite
Diorite (Spotted or Dalmatian Stone pattern)
Diorite
igneous
Shale or Mudstone
Argillaceous sedimentary rock
sedimentary
Puddingstone (Conglomerate)
Conglomerate (clastic sedimentary rock)
sedimentary
Fossilized Oyster in Flint
Gryphaea or Exogyra embedded in SiO2 (Flint/Chert)
fossil
Desert Rose Fragment (Atypical) / Weathered Chert
Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy
sedimentary
Calamites Fossil in Sandstone
Calamites (Genus) in Lithic Sandstone
sedimentary
Quartz Mineral
Silicon Dioxide (SiO2)
mineral
Clear Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (White/Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Citrine (Heat-treated Amethyst)
Citrine Quartz (SiO2)
Mineral (Tectosilicate)
Ironstone Concretion (Desert Varnish / Hematite-Goethite Nodule)
Iron oxide / hydroxide deposit (predominantly Fe2O3 and FeO(OH))
sedimentary
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Gravel Pebble)
Silicon Dioxide (SiO2)
mineral
Unidentified Small Rock
Unknown
undetermined
Ventifact
Wind-abraded rock (Ventifact)
sedimentary
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host
mineral
Lunar Meteorite (Feldspathic Breccia)
Lunar Achondrite (Regolith Breccia)
igneous
Note regarding baguette production (not a rock)
Digital text image - Somali language
not a rock
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Mudstone (Siltstone)
Lutite (primarily Quartz and Clay minerals with Hematite)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic