Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
igneous
Category
Anthropogenic (Man Made Product Subject To Geological Processes)
Browse anthropogenic (man made product subject to geological processes) specimens identified by the Rock Identifier community.
Galena
Lead(II) sulfide (PbS)
mineral
Muscovite Mica (on Quartz Matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Kimberlite
Kimberlite (Porphyritic Peridotite)
Igneous
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Fluorite
Calcium Fluoride (CaF2)
mineral
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Orthoclase (Potassium) Feldspar in Quartz
KAlSi3O8 (Potassium Aluminum Silicate)
igneous
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz (specifically Milky or Rose Quartz variant)
Silicon Dioxide (SiO2)
mineral
Milky Quartz (Tumbled Pebble)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Quartz (Milky Quartz Pebbles)
Silicon Dioxide (SiO2)
mineral
Fluorite (Purple variety)
Calcium Fluoride (CaF2)
mineral
Obsidian (worked into an arrowhead profile)
Obsidian (volcanic glass), primarily SiO2 (Silicon Dioxide)
igneous
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Red Jasper (Chert)
Silicon Dioxide (SiO2)
sedimentary
River Stone (Chert/Siltstone)
Cryptocrystalline Quartz (SiO2) with trace impurities
sedimentary
Quartz (Specifically Clear to Smoky Quartz point)
Silicon Dioxide (SiO2)
mineral
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Lavender Jade (Jadeite)
Jadeite - Sodium Aluminum Silicate (NaAlSi2O6)
metamorphic
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with impurities
sedimentary
Fluorite Octahedron
Fluorite (Calcium Fluoride, CaF2)
mineral
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing Mica)
mineral
Blue Chalcedony
Chalcedony (Silicon Dioxide, SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Quartz / Chert
Silicon Dioxide (SiO2)
Mineral / Sedimentary
Black Obsidian
Volcanic Glass (predominantly SiO2)
igneous
Pyrite
Iron Sulfide (FeS2)
mineral
Verde Antique Marble (Serpentinite)
Serpentinite (composed mainly of Serpentine group minerals, Mg3Si2O5(OH)4)
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
sedimentary
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral