Coal
Anthracite or Bituminous Coal (Carbon)
sedimentary
Category
Anthropogenic (Man Made Industrial Byproduct)
Browse anthropogenic (man made industrial byproduct) specimens identified by the Rock Identifier community.
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Vesicular Rhyolite
Rhyolite (High-silica volcanic rock)
igneous
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Mineral
Sandstone (Quartz-rich Cobble)
Arenite
sedimentary
Weathered chert or chalcedony nodule
Microcrystalline quartz (SiO₂), possibly silicified limestone or agate-like chalcedony
sedimentary
Pyrite
Pyrite (FeS2)
Mineral
Red Quartzite
Quartzite (Metamorphic quartz sandstone)
metamorphic
Aragonite
Aragonite (Calcium Carbonate - CaCO3)
mineral
Sandstone (Pebble)
Sandstone (SiO2 with matrix/cement)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone
Arenite (variable SiO2 composition)
sedimentary
Goldstone (aventurine glass)
Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone
gemstone
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Fossilized Coral (Coquina/Limestone)
Cnidaria Anthozoa (Fossilized)
sedimentary
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Quartzite
Metamorphic quartz rock (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
mineral
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
sedimentary
Quartzite
Metamorphic Quartz Arenite
metamorphic
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Sandstone
Arenite (specifically sublithic or quartz arenite)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
mineral
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Sandstone
Arenite (SiO2 primarily)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
sedimentary
Jasper (yellow/cream variety)
SiO₂ (Cryptocrystalline Quartz)
Sedimentary
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Quartzite
Quartzite (Metamorphic Quartz Sandstone)
metamorphic
Fossilized Shark Tooth (Fragment)
Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)
fossil
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Quartzite
Metamorphosed Quartz Sandstone
metamorphic
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Tumbled chalcedony (likely blue-gray agate)
Cryptocrystalline quartz, SiO₂; chalcedony/agate variety
mineral
Pearl
Aragonite (CaCO3) with Conchiolin
mineral