Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Agate (specifically Botswana or Banded Agate variety)
Chalcedony (Silicon Dioxide, SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (CaCO3)
Verde Antique Marble (Serpentinite)
Serpentinite (composed mainly of Serpentine group minerals, Mg3Si2O5(OH)4)
Serpentinite
Serpentinite (complex of Antigorite, Lizardite, and Chrysotile, Mg3Si2O5(OH)4)
Diamond
Native Carbon (C)
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2) with iridescent tarnish
Fluorite
Calcium Fluoride (CaF2)
Jasper (specifically Yellow or Picture Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Milk Quartz (or Milky Quartz)
Silicon Dioxide (SiO2)
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)
Quartz (likely tumbled or naturally water-worn)
Quartz (SiO₂ - Silicon Dioxide)
Quartz
Silicon Dioxide (SiO2)
Sandstone (Weathered)
Arenite (primarily SiO2)
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
Quartz
Silicon dioxide (SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Milky Quartz
Silicon dioxide (SiO2)
Laterite
Laterite (Ferricrete)
Red Sandstone
Arenite (with Iron Oxide)
Ironstone Concretion / Goethite-Hematite Nodule
Goethite/Hematite (α-FeO(OH) / Fe2O3)
Jasper
Silicon dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Fluorite (Purple Octahedron)
Calcium Fluoride (CaF2)
Agate (Moss or Plume Agate variety)
Silicon Dioxide (SiO2)
Fluorite (Rainbow Fluorite Tower)
Fluorite (Calcium Fluoride, CaF2)
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Basalt (Water-worn pebble)
Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)
Basalt (Weathered)
Extrusive mafic volcanic rock
Banded Agate (Botswana Agate)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with traces of Titanium, Iron, or Manganese
Milk Quartz (Vein Quartz)
Quartz (Silicon Dioxide, SiO2)
Scoria (Red Lava Rock)
Scoria
Sandstone (Ferruginous)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Sandstone
Arenite
Pumice
Pumicite (fine-grained pumice), Scoria (similar origin but denser and darker, usually basaltic)