Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Mineral
Category
Mineral Based Human Made Alloy
Browse mineral based human made alloy specimens identified by the Rock Identifier community.
Learn about Mineral Based Human Made Alloy in the encyclopedia
View all →
Granite Pegmatite
Coarse-grained Granite (SiO2 - Aluminum and Alkalies)
igneous
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Tumbled yellow-brown translucent stones, likely quartz/chalcedony
Quartz (SiO₂) or microcrystalline quartz (chalcedony); exact identification requires testing
mineral
Tumbled quartz (likely rose or milky quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Amethyst Quartz (Amethyst Geode)
Silicon Dioxide (SiO2) with iron impurities
mineral
Chert Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Granite
Phaneritic Plutonic Felsic Rock (K-Feldspar + Quartz + Plagioclase)
igneous
Silver Nuggets (Natural or Cast)
Native Silver (Ag)
mineral
Blue Sapphire
Corundum (Al2O3)
mineral
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
mineral
Schist
Schist (Crystalline metamorphic rock)
metamorphic
Quartz / Quartzite
Silicon Dioxide (SiO2)
metamorphic
Banded Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone (Ferruginous)
Sandstone (mainly SiO2 with Fe2O3 staining)
sedimentary
Zebra Jasper
Tumbled Opaque Chalcedony (SiO2)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4 nH2O
mineral
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite treated with acid
mineral
Polished serpentine
Serpentine-group minerals, chiefly lizardite and/or antigorite; approximate formula Mg₃Si₂O₅(OH)₄
metamorphic
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
metamorphic
Sandstone
Clastic Sedimentary Rock
sedimentary
Fossil Sea Urchin (Echinoid)
Echinoidea fossil (often replaced by silica or calcite)
fossil
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)
mineral
Banded Calcite
Calcium Carbonate (CaCO3)
mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
River Cobble (Phyllite or Quartzite)
Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)
metamorphic
Sandstone (Quartz-rich)
Sandstone (SiO2 dominated)
sedimentary
Halite
Halite (Sodium Chloride, NaCl)
mineral
Tiffany Stone
Bertrandite (Be4Si2O7(OH)2) mixed with Fluorite (CaF2), Opal, and Chalcedony
mineral
Silicon
Element Si
mineral
Sandstone
Arenite
sedimentary
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Chert Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Green Kyanite
Kyanite (Al2SiO5)
mineral
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
mineral
Felsic Drill Core (likely Gneiss or Granite)
Felsic Metamorphic Rock (Gneissic profile)
metamorphic
Opalite
Man-made opalized glass
mineral