Limestone Pebble
Limestone (Calcium Carbonate, CaCO3)
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Limestone Pebble
Limestone (Calcium Carbonate, CaCO3)
Black Sand (Magnetite/Heavy Mineral Concentrate)
Magnetite-rich Placers (Fe3O4)
Chert (Chert Nodule)
Microcrystalline quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert / Jasper
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (Fe2O3 rich)
Sandstone (Quartz-rich Cobble)
Arenite
Green Calcite
Calcium Carbonate (CaCO3)
Chert / Jasper
Silicon Dioxide (SiO₂)
Petrified wood
Silicified fossil wood; commonly composed of microcrystalline quartz (SiO₂)
Ferruginous Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Quartzite Pebble
Quartzite
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Anthracite Coal
Anthracite (Carbon C)
Likely polished leopard-skin jasper or brecciated jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the image alone
Bauxite
Aluminium ore / Hydrated aluminium oxides (AlOx(OH)3-2x)
Yellow Jasper
Silicon Dioxide (SiO2) with iron inclusions
Red Sandstone
Arenite (primarily Quartz with Iron Oxide coating)
Mica Schist
Mica Schist (primarily Muscovite and Biotite composition)
Chert (Jasper/Quartzite)
Microcrystalline Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Garnet in Schist
Almandine Garnet in Mica-Schist (Fe3Al2(SiO4)3)
Magnetite (Octahedral Crystal)
Magnetite (Fe3O4)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Sandstone
Arenite (primarily SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
Gemstone Art Panel (Jade, Quartz, and Soapstone)
Composite of silicate minerals (Nephrite, Quartz, Talc/Soapstone)
Desert Rose (Gypsum Variety)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Fossil brachiopod shell
Likely a spiriferid or orthid brachiopod; shell composed mainly of calcium carbonate (calcite)
Red Sandstone
Ferruginous Sandstone (SiO2 with Iron Oxide)
Agate
Silicon Dioxide (Chalcedony), SiO2
Bauxite
Bauxite (mixture of Hydrous Aluminum Oxides)
Fluorite
Calcium fluoride (CaF2)
Kaolin Clay in Saprolite Profile
Kaolinite (Al2Si2O5(OH)4) within Weathered Pegmatite/Granite
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)