Sandstone
Quartz Arenite (a type of sandstone composed of more than 90% quartz)
Category
Browse not a rock or mineral (anthropogenic material) specimens identified by the Rock Identifier community.
Sandstone
Quartz Arenite (a type of sandstone composed of more than 90% quartz)
Tiger's Eye
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
N/A (Non-Geological Specimen)
Diamond
C (Carbon)
Petrified Wood
Silicified Wood (SiO2)
Gneiss (Pebble)
Gneiss
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
Geode with Quartz and possibly Jasper/Hematite
Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides
Diamond
C (Carbon)
Diamond
Carbon (C)
Opalite
Man-made glass (traditionally simulated Opal)
Diamond (in jewelry setting)
Cubic Carbon (C)
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Milky Quartz
Silicon Dioxide (SiO2)
River Rock (Glacial Cobbles)
Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)
Greenschist
Greenschist (Chlorite Schist)
Geode (Unopened)
Siliceous Geode (SiO2)
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
Green Aventurine and Clear Quartz
Green Aventurine (Silicon Dioxide - SiO2 with Fuchsite inclusions); Clear Quartz (Silicon Dioxide - SiO2)
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Conglomerate
Conglomerate
Chalcedony (specifically Blue Chalcedony or Common Opal variety)
Silicon Dioxide (SiO₂)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Conglomerate
Conglomerate (a clastic sedimentary rock)
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Druzy Quartz on Chalcedony Matrix
Silicon Dioxide (SiO2)
Chert (White/Light Tan)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Halite
Halite (NaCl)
Fossil Shark Tooth
Carcharodon or Carcharias fossil (Vertebrate Fossil)
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
Pyrite
Pyrite (Iron Disulfide), FeS2
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
Chrysocolla (with Quartz and Azurite)
Hydrated copper phyllosilicate mineral [Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)]
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
Limonite (Iron Stone/Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2)