Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
sedimentary (biogenic)
Category
Mineral (Man Made Glass, Not Natural)
Browse mineral (man made glass, not natural) specimens identified by the Rock Identifier community.
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Diamond
Carbon (C)
mineral
Herkimer Diamond
Quartz (Silicon Dioxide) - SiO2
mineral
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Faceted pale-green gemstone, likely prasiolite or green quartz
Quartz (SiO₂), likely prasiolite; identification is uncertain from the photograph
gemstone
Tumbled purple jasper (likely)
Microcrystalline quartz/chalcedony, SiO₂, colored by iron and other trace minerals
mineral
Granite
Felsic intrusive igneous rock
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Tumbled ruby-bearing corundum
Corundum (Al₂O₃), likely ruby variety
mineral
Smoky Quartz Geode Cluster
Silicon Dioxide (SiO2)
mineral
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
mineral
Mica Schist
Mica Schist (Complex Silicate Rock)
metamorphic
Sandstone
Sandstone (composed mainly of Quartz, SiO2, and Feldspar)
sedimentary
Polished pink-and-white quartz bead bracelet
Quartz (SiO₂), likely rose quartz and milky quartz; some orange beads may be iron-stained quartz or pale carnelian
mineral
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Citrine Geode
Silicon Dioxide (Quartz variety, often heat-treated amethyst): SiO2
mineral
Chert Nodule / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Granite
Phaneritic plutonic rock (Silica-rich)
igneous
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
mineral
Black Tourmaline (Schorl)
NaFe3Al6(BO3)3Si6O18(OH)4
Mineral
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Small polished pink-and-white mineral pebble
Likely rose quartz or pale pink quartz; exact identification is uncertain from the image
mineral
Pink Granite (Water-worn Cobble)
Phaneritic Felsic Intrusive Igneous Rock
igneous
Granite
Intrusive igneous rock (Acidic)
igneous
Banded Sandstone / Quartzite Pebble
Sedimentary quartz arenite with liesegang banding
sedimentary
Emerald in Matrix
Beryllium Aluminum Silicate (Be3Al2(SiO3)6) with Chromium/Vanadium
gemstone
Blue calcite (likely)
Calcite, CaCO₃
mineral
Iron Ore (Limonite and Hematite)
Goethite/Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
mineral
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
sedimentary
Worry Stone
Weathered Quartzite or Sandstone
sedimentary
Banded Sedimentary Rock
Stratified Siliciclastic / Arenite or Siltstone with Mineral Bands
sedimentary
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Sandstone (Iron-stained Pebble)
Sandstone (Quartz/Hematite dominated)
sedimentary
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Black Onyx
Silicon Dioxide (SiO2)
mineral
Granite Gravel (Pebble)
Intrusive Felsic Igneous Rock
igneous
Granite
Granite (Phaneritic Quartz Monzonite)
igneous
Limonite (with goethite)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
mineral
Marble
Recrystallized Calcite (CaCO3)
metamorphic
Diamond (or Diamond Simulant like Cubic Zirconia)
Carbon (C) - if Diamond; Zirconium dioxide (ZrO2) - if Cubic Zirconia
mineral