Granite
Granitic intrusive igneous rock
Category
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
Granite
Granitic intrusive igneous rock
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Amygdaloidal Basalt with Secondary Minerals
Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)
Sandstone Cobble
Clastic Sedimentary (Sandstone)
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2 with various lithic fragments)
Goldstone (Synthetic Aventurescence Glass)
Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Fuchsite (Green Muscovite in Quartz)
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Vesicular Basalt (Iron-rich)
Scoriaceous Basalt / Oxidized Vesicular Basalt
Geode with Iron-Stained Quartz/Calcite
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix
Andesite
Intermediate Volcanic Rock (Andesite)
Granite
Phaneritic Plutonic Igneous Rock (composed of Quartz, Feldspar, and Mica)
Graphite
Graphite (Native Carbon, C)
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
Sandstone (with manganese staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Ferruginous)
Arenite (complex silicate composition with iron oxides)
Sandstone
Arenite (composed primarily of SiO2)
Schist/Phyllite
Metamorphic Schist (Chlorite Schist variety)
Biotite Schist
Biotite Schist (predominantly K(Mg,Fe)3AlSi3O10(OH,F)2)
Fossiliferous Shale
Laminated Mudrock with plant fossils
Schist (Biotite Schist)
Biotite-bearing Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)
Basalt with Quartz/Calcite Veins
Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2
Fuchsite
Chromium-bearing Muscovite [K(Al,Cr)2(AlSi3O10)(OH)2]
Mica
Phlogopite or Biotite group (KMg3(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
Opal
Hydrated amorphous form of silica (SiO2·nH2O)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Tree Agate
SiO2
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Sandstone (Ferruginous)
Arenite (Fe-bearing Clastic Sedimentary Rock)
Granular Sandstone
Arenite (variable composition, primarily SiO2)
Basalt with Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Mica Schist
Mica Schist (primarily Muscovite or Biotite Schist)
Diorite (Salt and Pepper Rock)
Phaneritic Plutonic Diorite (Plagioclase Feldspar + Amphibole/Biotite)
Sandstone (likely with Borings or Vesicular Basalt)
Clastic Sedimentary Rock (Sandstone)
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3/FeO(OH) cement)
Granite
Phaneritic Plutonic Felsic Rock (KAlSi3O8 - SiO2 - NaAlSi3O8)
Granite
Phaneritic Felsic Intrusive Igneous Rock
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2