Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
Wampum / Quahog Shell Fossil Fragment
Mercenaria mercenaria (Calcium carbonate, CaCO3)
Yellow Jasper
Chalcedony (SiO2) with goethite or limonite inclusions
Yellow Chert (River Stone)
Chert (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline quartz (SiO2)
Moldavite
SiO2 (+ Al2O3, FeO, K2O) - Natural Tektite Glass
Crinoid Stem Fossil
Class Crinoidea (Phylum Echinodermata), primarily Calcium Carbonate (CaCO3)
Transit Token (RTD Denver)
Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Flint (Chert)
Silicon Dioxide (SiO2)
Whetstone (Arkansas Stone)
Novaculite (SiO2)
Thunderegg (Ate Agate/Jasper Geode)
Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Apache Tear (Obsidian)
Obsidian / Amorphous Volcanic Glass (primarily SiO2)
Nephrite Jade / Greenstone
Tremolite-Actinolite solid solution series [Ca2(Mg,Fe)5Si8O22(OH)2]
Chert (Jasper/Quartzite variety)
Microcrystalline Silica (SiO2)
Sulfur on Aragonite
Sulfur (S) and Aragonite (CaCO3)
Pallasite Meteorite
Pallasite (Stony-iron meteorite; Fe-Ni alloy with (Mg,Fe)2SiO4 olivine)
Cupronickel Coin
Copper-Nickel Alloy (typically 75% Cu, 25% Ni)
Iron Meteorite (Campo del Cielo)
Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)
Arsenopyrite in Quartz Matrix
Arsenopyrite (FeAsS) with Quartz (SiO2)
Iron-rich quartzite or ferruginous metamorphic rock
Ferruginous quartzite, likely hematite/goethite-bearing quartzite; SiO₂ with Fe₂O₃/FeO(OH)
Moqui Marbles
Ironstone Concretions (Hematite / Goethite / Sandstone)
Chalcopyrite
Chalcopyrite (CuFeS2)
Diamond
Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.
Iron Meteorite
Siderite (Fe, Ni)
Fuchsite Quartzite
Fuchsite-bearing Quartzite
Black Chert
Chert (microcrystalline quartz)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Iron Meteorite (likely Chondrite or Iron-Nickel fragment)
Siderite (Iron Meteorite), primarily Fe-Ni (Iron-Nickel) alloy
Aquamarine
Beryl (Be3Al2Si6O18), specifically the blue-green variety
Diamond
Carbon (C)
Turquoise
Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Soapstone
Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)
Turquoise cabochon
Turquoise; hydrated copper–aluminum phosphate, approximately CuAl6(PO4)4(OH)8·4H2O (composition varies)
Weathered porphyritic basalt
Basalt, likely plagioclase-phyric basalt; primarily a fine-grained aggregate of plagioclase feldspar, clinopyroxene, and possibly olivine or iron-titanium oxides
Pyrite
Pyrite (Iron sulfide, FeS₂)
Iron Meteorite (likely an Individual specimen)
Iron Meteorite (Group IAB, IIAB, IIIAB, etc., Fe-Ni alloy)
Gold (Processed)
Gold (Au)