Diorite (River Cobble)
Intermediate plutonic igneous rock
Category
Browse mineral group specimens identified by the Rock Identifier community.
Diorite (River Cobble)
Intermediate plutonic igneous rock
Sandstone
Arenite (primarily composed of SiO2)
Arfvedsonite in Quartz (also labeled as Astrophyllite or Nuummite by collectors)
[Na][Na2][Mg4Fe2+](Si8O22)(OH)2 in SiO2
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
Granite
Phaneritic Felsic Igneous Rock
Sandstone (with cross-bedding)
Arenite (composed primarily of Quartz: SiO2)
Rose Quartz
SiO2 (Silicon Dioxide)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O)
Diorite (River Pebble)
Phaneritic Intermediate Plutonic Rock (Diorite)
Granite Gneiss
High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)
Granite
Course-grained intrusive igneous rock
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
Gneiss (Granitic Gneiss)
Gneiss (from German Gneis, related to 'spark')
Granitic Gneiss
Gneiss (High-grade Metamorphic Rock)
Gneiss
Gneiss
Pyrite (Fool's Gold) Ore
Iron Disulfide (FeS2)
Greenstone (possibly Basalt or Greenschist)
Greenschist (composed primarily of chlorite, actinolite, and epidote)
Quartzite
Quartzite (SiO2)
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Basalt
Basalt (Mafic volcanic rock)
Ferrosilicon Slag (Industrial Vitrified Glass)
Vitreous Silicate Residue
Basalt
Extrusive mafic igneous rock
Basalt
Basalt (primarily composed of Plagioclase Feldspar and Pyroxene)
Granite
Granite (Phaneritic intrusion / SiO2 + KAlSi3O8 + NaAlSi3O8)
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Quartzite
Quartzite (primarily SiO2)
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
Granite
Phaneritic Igneous Rock (Granite)
Quartz
Silicon Dioxide (SiO₂)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Gneiss (Metamorphic Rock)
Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)
Sodalite
Na8(Al6Si6O24)Cl2
Chrysocolla
Hydrated copper silicates (Cu, Al)2H2Si2O5(OH)4·nH2O
Quartz (Druzy or Geode fragment)
Silicon Dioxide (SiO2)
Amazonite
Amazonite (KAlSi3O8)
Citrine
Silicon Dioxide (SiO2)
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
Black Tourmaline (Schorl)
Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
Moqui Marble
Ironstone Concretion (Goethite/Hematite shell with Sandstone core)