Black Sapphire
Corundum (Al2O3 with iron and titanium impurities)
Category
Browse antropogenic (man made industrial byproduct) specimens identified by the Rock Identifier community.
Black Sapphire
Corundum (Al2O3 with iron and titanium impurities)
Raw Diamond
Diamond (pure Carbon, C)
Diamond
Diamond (pure Carbon, C)
Diamond
Carbon (C)
Diamond (Macled/Crystal fragment)
Carbon (C), isometric crystal system
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Bixbyite on Rhyolite
Bixbyite (Mn2+,Fe3+)2O3
Quartz
Quartz (SiO₂)
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Chromium (Chrome)
Chromium (Cr)
Chert / Jasper
Silicon Dioxide (SiO2)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Yellow Diamond (Faceted)
Diamond (C - Pure Carbon)
Diamond
Native Carbon (C)
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Peridot (Olivine)
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Greywacke
Dirty Sandstone (Lithic wacke)
Magnetite / Hematite mix (Iron Ore)
Fe3O4 (Magnetite) / Fe2O3 (Hematite)
Red Sandstone
Arenite (Fe2O3 rich)
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
Quartzite
Quartzite (primarily SiO2)
Quartz (Iron-stained or Ferruginous Quartz)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Crushed Limestone
Sedimentary Calcium Carbonate (CaCO3)
Quartz (Milky Quartz with Iron Staining)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Pegmatite (with smoky quartz and tourmaline/biotite)
Pegmatitic Granite
Granitic Pegmatite
Coarse-grained Igneous Rock (Granitic composition: KAlSi3O8, SiO2)
Rough Diamond
Diamond (pure carbon, C)
Diamond
Diamond (pure carbon, C)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Diamond
Native Carbon (C)
Rough Diamond
Diamond (pure Carbon, C)
Quartzite
Quartzite (primarily SiO2)
Fluorite (often referred to as Rainbow Fluorite)
Fluorite (Calcium Fluoride, CaF2)
Smoky Quartz and Biotite Schist
Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Tumbled/Polished Pebble)
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Green Fluorite (likely synthetic or heat-treated for jewelry)
Calcium Fluoride (CaF2)
Smoky Quartz (with inclusions)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)