Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Category
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Jadeite (Nephrite-Jadeite blend)
Jadeite (NaAlSi2O6)
Granite Pebble
Intrusive Felsic Igneous Rock (Granite)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Rhodonite
Rhodonite (MnSiO3)
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
Indigo Gabbro
Gabbro (MaFIC intrusive rock)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2)
Basalt
Extrusive mafic igneous rock
Basalt with Hematite staining
Extrusive mafic igneous rock with Fe2O3
Dalmatian Jasper
Peralkaline Feldspar Diorite/Rhyolite
Hematite
Iron(III) oxide (Fe2O3)
Basalt (Greenstone)
Basalt with chlorite/epidote (often referred to as Greenstone)
Schist
Schist
Slate
Slate (Foliated metamorphic rock consisting mainly of quartz and muscovite or illite)
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2 mixed with SiO2)
White Jade / White Chalcedony
Nephrite Jade (Ca2(Mg,Fe)5Si8O22(OH)2) or Chalcedony (SiO2)
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Granite Pebble
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Mica)
Eclogite
Eclogite (Pyrope garnet and Omphacite pyroxene)
Quartzite
Metamorphosed Quartz Sandstone
Banded Gneiss
Gneiss (pronounced "nice")
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartzite (specifically an iron-stained or Carnelian-colored variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Garnet
Garnet group [X3Y2(SiO4)3]
Chalcedony Geode Fragment
Cryptocrystalline Quartz (SiO2)
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Red Garnet
Almandine and Pyrope (Silicate minerals: Fe3Al2(SiO4)3 and Mg3Al2(SiO4)3)
Epidote (Unakite-related)
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Jadeite
NaAlSi2O6; Jadeite silicate mineral
Unakite (or Epidote-rich Granite)
Unakite (Metamorphosed Granite consisting of Epidote, Orthoclase, and Quartz)
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Granite
Granite
Schist
Chlorite/Mica Schist
Jadeite (Jade)
NaAlSi2O6 (Sodium Aluminum Silicate)
Dragon Stone (Dragon Blood Jasper)
Epidote with Pietersite or Red Jasper inclusions (varied SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))
Schist
Mica Schist
Sandstone Pebbles
Arenite (Sedimentary rock composed of sand-sized grains)