Gneiss
Gneiss (High-grade Metamorphic Rock)
Category
Browse mineral variant specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade Metamorphic Rock)
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Greenschist (Greenstone River Pebble)
Greenschist (Chlorite Schist)
Blue Quartzite
Quartzite (specifically a variety enriched with blue-coloring minerals)
Sandstone
Arenite (predominantly SiO2)
Dinosaur Bone (Fossilized)
Permineralized Bone (CaCO3 or SiO2 after Hydroxylapatite)
Labradorite
Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8
Red Garnet
Almandine and Pyrope (Silicate minerals: Fe3Al2(SiO4)3 and Mg3Al2(SiO4)3)
Nephrite (a form of Jade)
Nephrite (a variety of the mineral actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Limonite-pseudomorph after Pyrite (Prophecy Stone)
Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Quartz with Hematite Staining
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions
Diamond
Carbon (C)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Diamond
Diamond (C)
Granite
Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)
Green Aventurine
Aventurine (variety of Quartz - SiO2)
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
Schist
Crystalline Metamorphic Rock (Schistose)
Basalt (with possible mineral veining)
Basalt (Aphanitic Mafic Igneous Rock)
Quartzite with Iron Mineral Banding
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) staining
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Ferruginous Sandstone
Sandstone (rich in iron oxides/hydroxides)
Fluorite
Calcium Fluoride (CaF2)
Geode (Unopened)
Silica Concretion / Geode (Formula: SiO2 for quartz internal contents)
Green Aventurine
Quartz with Fuchsine inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Granite
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8, and Mica)
Chrysocolla
Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O
Granite Cobble
Granite
Basalt with Quartz/Feldspar Vein
Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)
Howlite and Purpurite druzy
Calcium Borosilicate Hydroxide (Howlite) and Manganese Phosphate (Purpurite)
Tumbled Moonstone
Feldspar (Orthoclase/Albite), KAlSi3O8
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Quartz Geode
Silicon Dioxide (SiO2)
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
Sandstone
Arenite (SiO2 primarily)
Granite
Granite (Felsic intrusive igneous rock)
Charoite
Charoite (Hydrated potassium, sodium, calcium, barium, strontium silicate hydroxide fluoride)
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
Gneiss
Gneiss
Copper-bearing Quartz (likely Malachite on Quartz matrix)
Cu2CO3(OH)2 (Malachite) on SiO2 (Quartz)
Greenstone
Metabasalt / Greenschist facies rock
Granite Pebble
Granite (Phaneritic intrusive igneous rock)