Anthracite Coal
Anthracite (Carbon-rich Sedimentary Rock)
sedimentary
Category
Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
Orange Quartzite / Carnelian Agate
Silicon Dioxide (SiO2)
metamorphic
Conglomerate
Clastic sedimentary rock (Conglomerate)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Sandstone (Quartz Arenite)
Sandstone (Chemical formula: primarily SiO2)
sedimentary
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
sedimentary
Quartzite with Quartz Vein
Quartzite (SiO2)
metamorphic
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
sedimentary
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Limestone (specifically Travertine or Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Quartz (Milky and Bull Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Beach Pebble)
Clastic sedimentary rock (primarily Quartz and Feldspar)
sedimentary
Chert (variations include Flint/Chalcedony)
Chert (SiO2 - Silicon Dioxide)
sedimentary
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz (Microcrystalline variety)
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Jasper (beads)
Silicon Dioxide (SiO2) with iron inclusions
Sedimentary Rock
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
mineral
Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
sedimentary
Travertine
Terrestrial Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz, SiO2)
sedimentary
Carnelian (Carnelian Agate)
Silicon dioxide (SiO2) - a variety of Chalcedony
mineral
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Mineral
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
sedimentary
Black Onyx
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Druzy Quartz Geode (likely Smokey Quartz variety)
Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.
Mineral structure/Rock
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Common)
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Sandstone (with potential iron-oxide weathering)
Arenite (SiO2 based)
sedimentary
Pebble
Clast (specifically a granule or small pebble)
Sedimentary
Chert (Jasper/Chalcedony variety)
Silicon Dioxide (SiO2)
sedimentary