Diamond (or Cubic Zirconia)
Crystallized Carbon (C) for Diamond; Zirconium Dioxide (ZrO2) for CZ
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Diamond (or Cubic Zirconia)
Crystallized Carbon (C) for Diamond; Zirconium Dioxide (ZrO2) for CZ
Quartzite
Quartzite (primarily SiO₂)
Sandstone
Arenite (SiO2 principal)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Sandstone
Arenite (composed primarily of SiO2)
Coal
Bituminous or Anthracite coal (carbon-rich sedimentary rock)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Sandstone
Sandstone (Sedimentary rock composed of silicate grains)
Sandstone
Arenite
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Rhodonite
(Mn,Fe,Mg,Ca)SiO3
Kimberlite
Kimberlite (Potassic ultramafic volcanic rock)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Quartzite
Quartzite (primarily SiO2)
Rutilated Quartz
Quartz (SiO2) with Rutile Inclusions (TiO2)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Chert / Flint (a variety of Chert)
Chert (SiO2)
Bauxite (Pisolitic Bauxite)
Bauxite (mixture of Hydrous Aluminum Oxides)
Sandstone
Arenite (SiO2 predominantly)
Amber
Succinite (Organic Gemstone)
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
Sandstone (Quartzite Pebble)
Arenite (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Sandstone (with biological crust)
Arenite (SiO2 based)
Chert (variations include Flint)
Chert (SiO2)
Sandstone
Arenite (SiO2 primarily)
Bauxite
Alumina-rich rock (consisting of Gibbsite, Boehmite, and Diaspore)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Halite
Halite (Sodium Chloride, NaCl)
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Gold Nugget
Native Gold (Au)
Limestone
Calcium Carbonate (CaCO3)
Quartz Pebble (Milky Quartz)
Silicon Dioxide (SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
Sandstone (likely Quartz Sandstone)
Arenite (composed primarily of SiO2)
Agate (Crazy Lace or Eye Agate)
Silicon Dioxide (SiO2)
Quartzite (with Metamorphic Foliation)
Quartzite (Recrystallized SiO2)
Halite
Halite (NaCl)