Quartz Pebble
Silicon Dioxide (SiO2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Pyrite (FeS2)
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
Red Vanadinite on Matrix
Vanadinite (Pb5(VO4)3Cl)
Greywacke
Dirty Sandstone (Lithic wacke)
Smoky Quartz
Silicon Dioxide (SiO2)
Red Garnet (likely Almandine or Pyrope)
Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)
Diamond
Carbon (C)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Garnet (Almandine variety)
Almandine, Fe3Al2(SiO4)3
Yellow Quartz
Silicon Dioxide (SiO2)
Yellow Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Pyrope Garnet
Magnesium aluminum silicate (Mg3Al2Si3O12)
Red Garnet (likely Almandine)
Almandine (Fe3Al2(SiO4)3)
Sodalite
Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)
Sodalite
Na8(Al6Si6O24)Cl2
Green Calcite
Calcium Carbonate (CaCO3)
Black Onyx
Chalcedony (SiO2) with parallel banding
Gold-bearing Quartz
Auriferous Quartz (SiO2 with Native Gold inclusion)
Quartz (Variety: Citrine or Tumbled Chalcedony)
Silicon Dioxide (SiO2)
Quartz Geode (Cracked)
Silicon Dioxide (SiO2)
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
Milky Quartz with Iron Oxide Staining
Quartz (Silicon Dioxide, SiO2)
Diamond (or Diamond Simulant like Cubic Zirconia)
Carbon (C) - if Diamond; Zirconium dioxide (ZrO2) - if Cubic Zirconia
Quartz (Iron-stained or Ferruginous Quartz)
Silicon Dioxide (SiO2)
Quartz (Milky/Smoky variety on matrix)
Silicon Dioxide (SiO2)
Sandstone
Arenite (Clastic Sedimentary Rock)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Rough Diamond
Diamond (pure Carbon, C)
Blue Sapphire
Corundum (Al2O3) with iron and titanium impurities
Dendritic Opal
Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Graphic Granite
Graphic Granite (a variety of Pegmatite)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Diamond (in a metal ring setting)
Diamond (Pure Carbon, C)
Garnet (likely Almandine)
Almandine - Fe3Al2(SiO4)3
Pyrite
Pyrite (Iron Disulfide), FeS2
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Obsidian (Apache Tear)
Obsidian (Amorphous Volcanic Glass / SiO2 with impurities)
Milky Quartz
Silicon Dioxide (SiO2)
Green Kyanite
Kyanite (Al2SiO5)
Smoky Quartz (Ferruginous Quartz)
Quartz (Silicon Dioxide, SiO2)