Quartzite
Quartzite (SiO2)
metamorphic
Category
Sedimentary Rock Or Mineral (Depending On Origin And Purity)
Browse sedimentary rock or mineral (depending on origin and purity) specimens identified by the Rock Identifier community.
Satin Spar (commonly sold as Selenite)
Hydrous Calcium Sulfate (CaSO4·2H2O)
mineral
Slate
Foliated low-grade metamorphic rock
metamorphic
Granite with Biotite and Quartz
Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, and K(Mg,Fe)3AlSi3O10(OH)2)
igneous
Gold-Bearing River Sand
Auriferous Placer Sand (Au + various minerals like SiO2 and Fe3O4)
sedimentary
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Mineral
Greenstone Celt (Polished Stone Axe)
Metamorphosed mafic rock (often Basalt or Diabase)
metamorphic
Obsidian (Arrowhead Lithic Tool)
Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)
igneous
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
sedimentary
Quartz with Mica Schist (Pegmatite Specimen)
SiO2 (Silicon Dioxide) and Phyllosilicates (Biotite/Muscovite)
Igneous/Metamorphic Hybrid
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Serpentinite
Serpentinite (containing minerals of the Serpentine subgroup: Antigorite, Lizardite, and Chrysotile; formula (Mg,Fe)3Si2O5(OH)4)
metamorphic
Sandstone
Arenite (SiO2 based)
sedimentary
Agate Geode
Silicon Dioxide (SiO2)
mineral
Calcite
Calcite (CaCO3)
Mineral
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Granite Cobble
Phaneritic Plutonic Felsic Rock
igneous
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Slate
Slate (Foliated Metamorphic Rock)
metamorphic
Sandstone (lithic/greywacke variant)
Clastic sedimentary rock (primarily SiO2 with rock fragments)
sedimentary
Shale
Laminated Mudstone
sedimentary
Amethyst
Silicon Dioxide (SiO2) with trace Iron impurities
mineral
General Rock and Mineral Collection (Center: Angelite / Blue Anhydrite)
Anhydrite (Calcium Sulfate, CaSO4)
Mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (likely Arkose or Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Peridot
Olivine ((Mg, Fe)2SiO4)
mineral
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
sedimentary
White Howlite
Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)
mineral
Granular Sandstone
Arenite (variable composition, primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartzite with Quartz Vein
Metamorphosed sandstone (SiO2)
metamorphic
Chert (Common Opal/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
sedimentary
Banded Sandstone
Arenite (with iron oxide banding)
sedimentary
River Rock (likely Quartzite or Chert)
Quartzite (primarily SiO2)
metamorphic
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
sedimentary
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Caliche (also known as hardpan, calcrete, kankar)
Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.
Mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Apatite
Apatite Group (e.g., Fluorapatite Ca5(PO4)3F, Chlorapatite Ca5(PO4)3Cl, Hydroxylapatite Ca5(PO4)3(OH))
mineral