Greenstone (likely chlorite- or actinolite-rich metabasalt)
Metamorphosed mafic volcanic rock; commonly greenschist-facies basalt, composed chiefly of chlorite, actinolite, epidote, and albite
Category
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Greenstone (likely chlorite- or actinolite-rich metabasalt)
Metamorphosed mafic volcanic rock; commonly greenschist-facies basalt, composed chiefly of chlorite, actinolite, epidote, and albite
Rounded dark-gray rock, likely diorite or andesite
Probable diorite (plagioclase and hornblende/pyroxene); identification is limited by the image
Exposed shoreline bedrock and sediment
Unidentified natural rock; the image does not show enough detail for a specific geological identification
Granite pebble
Granite; predominantly quartz, feldspar, and mica
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Red garnet crystal cluster
Most likely almandine garnet, Fe₃Al₂(SiO₄)₃; exact species cannot be confirmed from the image alone.
Quartz on Schist
Silicon Dioxide (SiO2) on Foliated Metamorphic Rock
Fluorite (Rainbow, Purple-Blue Tumbled)
Calcium Fluoride (CaF2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Basalt with Secondary Mineralization (Likely Zeolites or Calcite)
Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)
Gneiss (specifically Banded Gneiss)
Gneiss
Granite
Phaneritic Felsic Igneous Rock
Tumbled Mixed Gemstones and Rocks
Various mineral species including quartz (SiO2) and silicate minerals
Rounded granite pebble
Granite, a quartz–feldspar–mica plutonic rock
Quartz with Mineral Inclusions
Silicon Dioxide (SiO2)
Green glass-like mineral specimen, likely fluorite
Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass
Quartz Mineral
Silicon dioxide (SiO2)
Quartz Mineral
Silicon Dioxide (SiO2)
Quartz Mineral
Silicon Dioxide (SiO2)
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Quartz Mineral
Silicon Dioxide (SiO2)
Gold Mineral
Native Gold (Au)
Weathered copper-bearing rock, possibly chrysocolla-bearing quartz or host rock
Indeterminate from the photo; possible chrysocolla (hydrated copper silicate) with quartz or other host minerals
Travertine
Calcium Carbonate (CaCO3)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Granite
Intrusive igneous felsic rock
Milky quartz cluster
Quartz, silicon dioxide (SiO₂)
Quartz Vein in Hematitic Siltstone
Hydrothermal Quartz (SiO2) in Ferriferous Matrix
Sandstone with Manganese Dendrites
Clastic Sedimentary Rock (SiO2 based with MnO2 inclusions)
Pink-purple rough mineral specimen (possibly lepidolite-bearing mica)
Lepidolite, a lithium-rich mica; identification is uncertain from the photo
Jade (likely Jadeite)
Jadeite (a pyroxene mineral) or Nephrite (a variety of amphibole mineral)
Yellow iron-oxide-rich mineral/rock fragment
Likely limonite/goethite (hydrated iron oxides; commonly approximated as FeO(OH)·nH₂O)
Banded quartz-rich rock (possibly pegmatite)
Likely quartz–feldspar pegmatite; identification is tentative from the photo
Likely garnet-bearing rock (possibly almandine garnet in dark matrix)
Garnet, probably almandine (Fe₃Al₂(SiO₄)₃); host rock is not identifiable from this image
Sodalite
Na8Al6Si6O24Cl2
Milky quartz (rough quartz specimen)
Quartz, silicon dioxide (SiO₂)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Mixed rock and mineral collection
Unidentified assortment of geological specimens; individual species cannot be determined from the image
Granite
Granite (Plutonic Igneous Rock)
Granitic Gneiss
Gneiss (Metamorphic rock of granitic composition)