Dark gray crystalline rock, possibly basalt
Basalt (tentative; plagioclase–pyroxene–iron oxide assemblage)
igneous
Category
Mineral And Metamorphic Rock
Browse mineral and metamorphic rock specimens identified by the Rock Identifier community.
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Unidentified gray mineral/rock fragment
Indeterminate from image; possibly quartz-rich material or mica-bearing schist
mineral
Amethyst and Ruby in Zoisite
Silicon Dioxide (SiO2) and Anyolite (Zoisite-Hornblende-Ruby mix)
mineral and metamorphic rock
Raw Emerald in Schist Matrix
Beryl (Be3Al2Si6O18) in Mica Schist
Mineral in Metamorphic Rock
Serpentinite (likely serpentinized ultramafic rock)
Serpentine-group minerals, chiefly antigorite/lizardite; commonly derived from peridotite
metamorphic
Small quartz-rich pebble, possibly milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Quartz-rich pebble, possibly milky quartz with dark inclusions
Quartz (silicon dioxide, SiO₂), likely with iron-oxide or mica inclusions
mineral
Biotite Mica Schist
Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2
metamorphic
Banded Gneiss Pebble
Gneiss (Metamorphic Rock)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded gneiss (probable)
Gneiss, commonly quartz–feldspar–mica bearing
metamorphic
Likely quartz-rich stone, possibly milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Quartz-rich rock, possibly milky quartz
Quartz (silicon dioxide, SiO₂), possibly with feldspar or mica inclusions
mineral
Quartz-rich metamorphic rock, likely milky quartz or quartzite
Quartz (SiO₂); possibly quartzite composed predominantly of recrystallized quartz
metamorphic
Weathered quartz-rich rock, possibly milky quartz or quartzite
Quartz (SiO₂), likely with iron-oxide staining and minor feldspar or carbonate impurities
mineral
Chalcopyrite-bearing metamorphic rock (possibly bornite/chalcopyrite ore)
Likely quartz–sulfide rock containing chalcopyrite (CuFeS₂); identification from the image is tentative
metamorphic
Gneiss
Gneiss (foliated metamorphic rock)
metamorphic
Frosted Quartz
Silicon Dioxide (SiO2)
mineral
Schist
Crystalline Metamorphic Rock (Schistose)
metamorphic
Pink Sapphire
Corundum (Al2O3)
gemstone
Tumbled quartz-rich stone, possibly milky quartz or quartzite
Quartz (SiO₂), potentially quartzite (metamorphic rock)
mineral
Pink Quartz Cluster
Silicon Dioxide (SiO2)
mineral
Chalcopyrite
CuFeS2
mineral
Schist
Schist (metamorphic rock)
metamorphic
Small red-brown mineral or rock fragment
Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide
mineral
Rock and Mineral Collection
Mixed Geological Specimens
mineral
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly milky quartz or chalcedony
mineral
Likely milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Clear quartz crystal pendant
Quartz (silicon dioxide, SiO₂)
mineral
Greenstone (likely serpentinite or chlorite-rich metamorphic rock)
Probable serpentinite/chlorite schist; commonly dominated by serpentine-group minerals, chlorite, talc, and magnetite
metamorphic
Biotite-bearing gneiss or schist
Quartz–feldspar–biotite metamorphic rock
metamorphic
Milky quartz with iron-oxide staining
Quartz (SiO₂), likely with goethite/limonite coatings
mineral
Gneiss
Gneiss (Foliated Metamorphic Rock)
metamorphic
Mica Schist
Foliated Metamorphic Rock (Schist)
metamorphic
River Pebble (Gneiss or Quartzite mixture)
Metamorphic rock (Commonly Gneissic)
metamorphic
Quartz Vein in Pelite (Metamorphic Rock)
Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)
metamorphic
Schist
Mica Schist (Metamorphic rock)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Weathered greenish metamorphic rock, likely serpentinite
Serpentinite, dominated by serpentine-group minerals (commonly antigorite, lizardite, or chrysotile)
metamorphic
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Igneous
Tumbled clear quartz
Quartz (SiO₂)
mineral
Tumbled clear quartz
Quartz (silicon dioxide, SiO₂)
mineral