Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Category
Antropogenic (Man Made Material)
Browse antropogenic (man made material) specimens identified by the Rock Identifier community.
Learn about Antropogenic (Man Made Material) in the encyclopedia
View all →
Green cabochon gemstone, likely aventurine or dyed chalcedony
Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony
gemstone
Black-and-white agate geode pendant
Agate (microcrystalline quartz, SiO₂), likely a hollow geode slice with chalcedony and drusy quartz
mineral
Red Sandstone
Quartz Arenite (iron-stained) / SiO2
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Blue glassy cabochon, likely blue quartz or synthetic glass
Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive
gemstone
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
mineral and glass
Sunstone (Aventurine Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3
mineral
Granite
Granite (Mainly Quartz SiO2, Feldspar KAlSi3O8, and Mica KAl2(AlSi3O10)(OH)2)
Igneous
Green cabochon gemstone, likely nephrite jade
Nephrite jade—interlocking amphibole fibers, chiefly tremolite-actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
gemstone
Amber-set ring
Amber (fossilized plant resin; organic mineraloid), set in a metal ring
gemstone
Tumbled amethyst quartz
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
gemstone
Polished blue stone, likely sodalite or dyed agate
Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing
mineral
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Multicolor quartz bead bracelet
Quartz (silicon dioxide, SiO₂); bead colors may be from different varieties or treated quartz
gemstone
Tumbled brown chalcedony or jasper
Microcrystalline quartz, SiO₂; possibly iron-bearing jasper
mineral
Tourmalinated quartz point
Quartz (SiO₂) with black tourmaline (schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) inclusions
mineral
Porcelain (Kaolin-based)
Alumina silicate ceramic (composed primarily of Kaolinite: Al2Si2O5(OH)4)
metamorphic (man-made/engineered)
Chert (Flint / Jasper)
Silicon Dioxide (SiO2)
sedimentary
Native Silver
Silver (elemental Ag)
mineral
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Crushed Stone / Gravel
Aggregatus saxum (variable mineral composition)
sedimentary
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Polished rutilated quartz cabochon
Quartz (SiO₂) with rutile inclusions (TiO₂)
gemstone
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
man-made alloy (metallic)
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint / Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Greenstone
Metamorphic mafic rock (chlorite-actinolite-epidote schist)
metamorphic
Flint / Chert
Microcrystalline quartz (SiO2)
sedimentary
Tektite (Indochinite)
Tektite (Amorphous Silica Glass)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)
sedimentary
Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)
Quartz, silicon dioxide (SiO₂)
mineral
Quartzite
Metamorphic quartz rock (SiO2)
metamorphic
Chalk
Carbonate rock (mainly CaCO3)
sedimentary
Engineered Quartz (Quartzite look-alike)
Silicon Dioxide (SiO2) composite
mineral-based composite
Fulgarite
Fulgurite (Lechatelierite / Vitrified Sand)
igneous
Carnelian cabochon
Orange-red variety of chalcedony (microcrystalline quartz), SiO₂
gemstone
Coquina
Biogenic Limestone (Coquina)
sedimentary
Chalk
Calcite (CaCO3)
sedimentary