Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Category
Browse man made glass specimens identified by the Rock Identifier community.
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Chalk
Carbonate rock (mainly CaCO3)
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Granite
Phaneritic Felsic Igneous Rock
Diamond (in Jewelry)
Carbon (C)
Chalcedony (Common Opal/Chert variety)
Silicon Dioxide (SiO2)
Diamond
Diamond (pure Carbon, C)
Quartz
Silicon Dioxide (SiO₂)
Diamond
Carbon (C)
Quartz
Silicon dioxide (SiO2)
Fluorite with Rhodochrosite
Fluorite (CaF2) and Rhodochrosite (MnCO3)
Quartz
Quartz (SiO2)
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
Quartz (Float/Abraded)
Quartz (SiO₂)
Quartz (likely tumbled or naturally water-worn)
Quartz (SiO₂ - Silicon Dioxide)
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Quartz (pebble)
Quartz (SiO₂)
Diamond
Native Carbon (C)
Diamond
Carbon (C)
Slag
Anthropogenic Vitrophyre (Iron or Smelting Slag)
Diamond
Diamond (pure carbon C)
Limestone
Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Diamond
Diamond (pure Carbon, C)
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Basalt
Basalt
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Quartz Geode/Cluster
Quartz (SiO2)
Diamond
Diamond (pure Carbon, C)
Diamond
Carbon (C)
Obsidian (Apache Tear)
Obsidian / Amorphous Volcanic Glass (main component: SiO2)
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Diamond in Kimberlite
Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)