Granitic Gravel Piece
Granite (Felsic Plutonic Rock / SiO2 with Al2O3, K2O, Na2O)
Category
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Granitic Gravel Piece
Granite (Felsic Plutonic Rock / SiO2 with Al2O3, K2O, Na2O)
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
Quartzite Pebble
Quartzite (SiO2)
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
White Quartz
Silicon Dioxide (SiO2)
Jadeite
NaAlSi2O6 (Sodium Aluminum Silicate)
Milky Quartz
Silicon Dioxide (SiO2)
Massive Quartz (Milky or Gray)
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Shale
Lutaceous sedimentary rock
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (Quartz-rich)
Arenite (primarily SiO2)
Quartz / Rock Crystal
Silicon Dioxide (SiO2)
Copper Ore (with Malachite and Azurite)
Hydroxide copper carbonate (Cu2CO3(OH)2 / Cu3(CO3)2(OH)2)
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Hematite
Iron(III) oxide (Fe2O3)
Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)
Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.
Granite Pebble (Salt and Pepper Granite)
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)
Clear Quartz
Silicon Dioxide (SiO2)
Granite
Phaneritic Plutonic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Apatite
Fluorapatite, Chlorapatite, and Hydroxylapatite (Ca5(PO4)3(F,Cl,OH))
Quartzite (or Milky Quartz pebble)
Quartzite (primarily Silicon Dioxide, SiO2)
Specular Hematite
Hematite (Fe2O3)
Granite (with alteration)
Granite (Felsic intrusive igneous rock)
Diamond in Kimberlite
Kimberlite host rock with C (Carbon) inclusion
Orange Quartzite (or Aventurine Quartz)
Quartzite (primarily SiO2 with Hematite or Goethite inclusions)
Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Pink Granite
Phaneritic plutonic igneous rock (Alkali-feldspar granite)
Ferromanganese Nodule
Polymetallic Nodule (composed primarily of MnO2 and Fe2O3)
Red Sandstone
Arenite (composed primarily of SiO2 with Fe2O3 cementation)
Coquina / Fossiliferous Limestone
Coquina (composed primarily of Calcium Carbonate / CaCO3)
Gold-bearing Quartz with Iron Oxides
Quartz (SiO2) with Limonite/Goethite (FeO(OH)) and Pyrite (FeS2)
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
Quartz
Silicon Dioxide (SiO2)
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Amygdaloidal Basalt with Secondary Minerals
Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)
Quartz (specifically Milky or Clear Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)