Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Category
Browse sedimentary rock (metamorphosed) specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Laterite
Laterite (Iron/Aluminum-rich oxide)
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
Chert (often referred to as 'Jasper' when red)
Chert (microcrystalline quartz, SiO₂)
Sandstone
Quartz Arenite (a type of sandstone composed of more than 90% quartz)
Gneiss
Gneiss (a type of metamorphic rock)
Banded Chert (or Flint)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Rock Crystal Quartz
Quartz (SiO₂)
Limestone
Calcium Carbonate (CaCO3)
Barite Rose (Desert Rose)
Barium Sulfate (BaSO4)
Dragon Blood Jasper
Epidote with Red Jasper inclusions (SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
River Cobble (Phyllite or Quartzite)
Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)
Quartzite River Rock
Quartzite (primarily SiO2)
Septarian Nodule (Dragon Stone)
Septarian concretion (Complex of Calcite, Aragonite, and Limestone/Clay)
Chert (Tan/Yellow variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert Nodule (Commonly known as a Flint or River Cobble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized Favosites (Honeycomb Coral)
Favosites (Genus), Phylum Cnidaria, Class Anthozoa
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')
Calcium Carbonate (CaCO3)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Red Jasper
Jasper (Silicon Dioxide with iron oxide inclusions), SiO2
Gneiss
Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)
Chalcedony (Quartz Nodule)
Silicon Dioxide (SiO2)
River Quartzite / Tumble-Polished Quartz
Quartzite (SiO2)
Jasper (specifically a banded or dark variety)
Silicon Dioxide (SiO2) with impurities
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite or Iron Oxide inclusions
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Marble (Calcitic)
Metamorphosed Limestone (CaCO3)
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Quartzite
Metamorphosed Sandstone (SiO2)
Septarian Nodule (Dragon Stone) sphere
Septarian concretion (Calcite, Aragonite, and Limestone)