Jasper or Chalcedony
Microcrystalline Quartz (SiO2)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Jasper or Chalcedony
Microcrystalline Quartz (SiO2)
Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Note: The image provided is a fabric sock, not a geological specimen.
Polyester-Cotton Blend with Elastane
Unidentified Rock Fragment
Unknown
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Tiger's Eye
Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8
Quartzite (Water-worn Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Pumice
Pumicite
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Gravel specimen)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartzite
Quartzite (SiO2)
Pumice
Vesicular Rhyolite (highly vesicular igneous volcanic rock)
Basalt
Basalt (Composition primarily Plagioclase feldspar, Pyroxene, and Olivine)
Basalt
Basalt
Scoria (Lava Rock)
Scoria (highly vesicular extrusive igneous rock)
Basalt (Vesicular/Scoriaceous)
Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
Basalt (River or Beach Pebble)
Basalt (Mafic Extrusive Igneous Rock)
Quartzite Pebble
Quartzite (primarily SiO2)
Ferruginous Sandstone (with Iron Oxide staining)
Clastic Sedimentary Rock - Quartz Arenite/Wacke
Basalt with Vesicular Surface
Basalt (Mafic Extrusive)
Yellow Chalcedony
Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)
Epidote (likely Pistacite in Epidosite rock)
Epidote: Ca2(Al,Fe)3(SiO4)3(OH)
Himalayan Salt
Halite (mineral name), chemical formula NaCl (sodium chloride). Generally, 'Himalayan Salt' is a trade name for evaporite minerals from specific regions.
Amethyst
Quartz (Silicon Dioxide, SiO2) with iron impurities
Amber (Dark/Black Variety)
Succinite (Resinite), C10H16O
Basalt with Epidote (Greenstone)
Amygdaloidal Basalt (Ca2(Al, Fe)3(SiO4)3(OH) inclusions)
Iolite (Cordierite)
Magnesium Iron Aluminum Silicate (Mg,Fe)2Al4Si5O18
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2 (Tremolite-Actinolite series)
Basalt
Extrusive Mafic Igneous Rock
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Pink Granite / Gneiss
Felsic Plutonic Rock (Granite) with Gneissic banding
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Banded Onyx (Calcite Marble)
Calcite (CaCO3) - Trap-rock or Cave Onyx
Diamond
Diamond (pure carbon; C)
Schist
Schist (various compositions)
Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
Milky Quartz
Silicon Dioxide (SiO2)
Tumbled Carnelian and Quartz Mix
Silicon Dioxide (SiO2) with iron oxide impurities