Basalt Pebble
Basalt (Mafic volcanic rock)
Category
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Basalt Pebble
Basalt (Mafic volcanic rock)
Dalmation Jasper (Dalmation Stone)
Perthitic feldspar-quartz-amphibole rock
Agate Geode
Banded Chalcedony (Silicon Dioxide, SiO2) with Quartz crystals
Unakite
Epidotized Granite
Ammonite Fossil in Limestone Matrix
Ammonoidea (subclass) in Calcium Carbonate (CaCO3)
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Scoria (Lava Rock)
Scoria (extrusive volcanic rock)
Diorite (River Rock)
Intermediate plutonic igneous rock
Scoria (Lava Rock)
Scoria (Mafic volcanic rock)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Riverstone Quartzite
Quartzite (primarily SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Agate (Thunderegg segment)
Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony
Yellow Quartzite
Quartzite (SiO2)
Amethyst (Chevron Amethyst)
Amethystine Quartz (SiO2)
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Petrified Wood
Silicified Wood (SiO2)
Chert (variations include Flint or Jasper)
Cryptocrystalline Quartz (SiO2)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Schist
Schist (Crystalline metamorphic rock)
Quartz Vein in Pelite (Metamorphic Rock)
Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Granatic Pegmatite
Pegmatitic Granite
Copper-bearing Quartz (likely Chrysocolla or Malachite staining)
Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock
Jasper
Silicon dioxide (SiO2)
Chert (specifically Gray Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Coquina
Bioclastic Limestone
Quartz / Common Opal
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)
White Quartz (Tumbled)
Silicon Dioxide (SiO2)
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Granite
Granite (felsic intrusive igneous rock)
Unakite
Epidotized Granite
Unakite
Unakite (Epidotized Granite)
Basalt
Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)
Unakite
Epidotized Granite
Unakite
Unakite (Epidotized Granite)