Quartz-bearing granite or pegmatite fragment
Likely granitic material composed mainly of quartz (SiO₂), feldspar, and possibly biotite or hornblende
Category
Browse metamorphic (localized) or sedimentary specimens identified by the Rock Identifier community.
Quartz-bearing granite or pegmatite fragment
Likely granitic material composed mainly of quartz (SiO₂), feldspar, and possibly biotite or hornblende
Riverstone (Quartzite or Siltstone cobble)
Quartzite (primarily SiO2)
Granite-like gneiss
Foliated granitic gneiss, composed mainly of quartz, feldspar, and mica
Zebra marble
Banded calcite marble, commonly called zebra marble; chiefly calcite (CaCO₃), sometimes with dolomite and dark silicate or carbonaceous minerals
Black slate
Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals, chlorite, and quartz
Dark rounded pebble
Likely basalt or another fine-grained mafic volcanic rock; exact identification is uncertain from the image
Banded gneiss pebble
Gneiss, a foliated metamorphic rock, likely quartz–feldspar–mica gneiss
Quartz fragment
Quartz (silicon dioxide, SiO₂), likely milky or smoky quartz
Dark gray rounded river pebble
Likely basalt or fine-grained volcanic rock; exact identification requires testing
Blue Calcite
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcium Carbonate (CaCO3)
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
Muscovite
KAl2(AlSi3O10)(OH)2
Kyanite
Kyanite (Al2SiO5)
Phyllite
Phyllite (Intermediate grade metamorphic rock)
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
Chalk (or Soapstone Marking Stick)
Calcium Carbonate (CaCO3) / Hydrous Magnesium Silicate (Mg3Si4O10(OH)2)
Milky Quartz
SiO2
Clear Quartz
Silicon dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Quartz pebble
Silicon dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Quartz
Silicon dioxide (SiO2)
Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Optical Calcite
Calcium Carbonate (CaCO3)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Mixed Mineral Collection
Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz Crystal
Silicon Dioxide (SiO2)
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (Chalcedony), SiO2
Agate
Chalcedony (SiO2)
White Quartz
Silicon Dioxide (SiO2)
Smoky Quartz / Chalcedony
Silicon Dioxide (SiO2)
White Quartz Beads
Silicon Dioxide (SiO2)