General river rock or weathered cobble
Mixed rock composition
Category
Browse metamorphic rock specimens identified by the Rock Identifier community.
General river rock or weathered cobble
Mixed rock composition
Apatite
Fluorapatite (Ca5(PO4)3F)
Blue Sapphire
Corundum (Al2O3 - Aluminum Oxide)
Quartz (Milky Quartz)
Silicon Dioxide (SiO₂)
Gemstone Sand (Mineral Assortment)
Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)
Ferruginous Quartz Cobble
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Milky Quartz (Druzy Geode fragment)
Silicon Dioxide (SiO2)
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
Schist (Micaceous Schist)
Schist (containing mainly Muscovite and Quartz)
Quartzite
Quartzite (SiO2)
Serpentinite
Serpentinite (complex of lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)
Quartzite with Hematite staining
Metamorphic Quartzite (SiO2) with Ferruginous Oxides
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Quartzite (River Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartzite
Quartzite (primarily SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Ferruginous Quartzite (Red Quartzite)
Quartzite (primarily SiO2 with Fe2O3 inclusions)
Sapphire (Corundum)
Corundum (Al2O3)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Greenstone / Epidosite
Epidosite (primary minerals: Epidote and Quartz)
Biotite Mica
K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2)
Ruby (Pinkish-Red)
Corundum (Al2O3 with Chromium trace)
Milk Quartz (White) and Yellow Aventurine (Yellow)
Silicon Dioxide (SiO2)
Black Onyx
Silicon Dioxide (SiO2) with parallel banding
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Schist
Mica Schist
Quartzite
Quartzite (SiO2 silicon dioxide)
Quartzite
Quartzite (primarily SiO2)
Quartz Mineral Specimens
Quartz (Silicon Dioxide, SiO2)
Mica Schist
Mica Schist (predominantly Muscovite/Biotite)
Gneiss
Gneiss
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Schist with Quartz/Mica
Mica Schist (primarily Muscovite and Quartz)
Schist
N/A (a rock type, not a mineral formula)
Quartz (Milky/Crystal Variety)
Silicon Dioxide (SiO2)