Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
Category
Browse man made alloy (metallic) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Coquina / Fossiliferous Limestone
Calcareous bioclastic sedimentary rock (CaCO3)
Diorite (Gneissic)
Diorite
Pearl
Aragonite (CaCO3) with Conchiolin
Diabase (Greenstone)
Diabase (Dolerite)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Sandstone
Arenite (composed primarily of SiO2)
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8) with Albite inclusions
Chert (and/or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Diorite
Phaneritic Intrusive Igneous Rock (composed of Plagioclase feldspar, Hornblende, and Biotite)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Jasper
Silicon Dioxide (SiO₂)
Coquina
Biogenic Limestone (CaCO3)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Granite
Phaneritic Felsic Intrusive Igneous Rock
Diamond (Cluster Ring)
Carbon (C)
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
Diamond in Kimberlite
Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)
Chert (specifically Jasper or Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Coquina
Bioclastic Limestone (Coquina)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
Onyx (Black) and Mother of Pearl Inlay
Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl
Moonstone (specifically Rainbow Moonstone / White Labradorite)
White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)
Chalk
Calcium Carbonate (CaCO3)
Specular Hematite
Specularite (Iron Oxide, Fe2O3)
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
Lepidolite
K(Li,Al)3(Si,Al)4O10(F,OH)2
Hematite
Iron(III) oxide (Fe2O3)
Pyrite (on the right) and Magnetite or Hematite (on the left)
Iron Sulfide (FeS2) and Iron Oxide (Fe3O4 or Fe2O3)
Sandstone
Arenite (primarily SiO2)
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)