Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Category
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Jasper (Cream/Yellow variety)
Silicon Dioxide (SiO2) with impurities
Diorite
Intrusive Igneous Rock (Intermediate Composition)
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) / Scoriaceous Basalt (Host Rock)
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)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
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)
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Rose Quartz
SiO2 (Silicon Dioxide)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (Amorphous SiO2 + SiO2 inclusions)
Gneiss (Metamorphic Rock)
Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)
Quartz
Silicon Dioxide (SiO₂)
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
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Milky Quartz
Silicon Dioxide (SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities