Chert (often called Flint or Jasper)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Category
Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material) in the encyclopedia
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Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Iron-stained quartz-rich rock, possibly jasper or chert
Microcrystalline quartz (SiO₂) with iron oxides/hydroxides
mineral
Moldavite
Moldavite (Silica-rich glass, SiO2 + Al2O3)
tektite
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossiliferous Limestone containing a Brachiopod or Mollusk Impression
Biogenic Sedimentary Rock / Fossiliferous Limestone
sedimentary
Pyrite
Pyrite (Iron Disulfide), FeS2
Mineral
Shark Tooth Fossil
Otodus obliquus (or similar prehistoric lamniform shark tooth)
fossil
Fossilized Shark Tooth (Otodus)
Otodus obliquus
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Chert (Jasper/Chalcedony mix)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Chert (specifically Flint or Jasper variant)
Cryptocrystalline Quartz (SiO2)
sedimentary
Mixed tumbled gemstone collection
Varied minerals, likely including amethyst, sodalite/lapis lazuli, quartzite or aventurine, jasper, and agate/chalcedony
gemstone
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Ironstone Concretion
Ironstone (primarily Siderite or Limonite)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Polished agate/chalcedony slab
Microcrystalline quartz (SiO₂), chiefly chalcedony with iron-oxide inclusions
gemstone
Quartz
Silicon Dioxide (SiO2)
mineral
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
mineral
Peridot in Matrix
Olivine ((Mg,Fe)2SiO4)
mineral
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth
Chondrichthyes (Class) - likely Carcharodon or Otodus genus
fossil
Fossil Shark Tooth (Sand Tiger Shark type)
Carcharias sp. (likely Odontaspis)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Petrified Wood
Silicified Wood (mainly Quartz / SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Nephrite Jade
Nephrite
Mineral/Rock
Moss Agate
Moss Agate (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is microcrystalline Quartz)
Amber with dark mineral/organic inclusions
Fossilized plant resin (amber; chiefly polymerized diterpenoid resin)
gemstone
Bloodstone (Heliotrope)
SiO2 (Silicon Dioxide with inclusions of Chlorite, Amphibole, or Hematite)
mineral
Jasper with Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Rhinestone (or glass crystal)
Silicon dioxide (if glass) / Various
Mineral/gemstone imitation
Hematite
Hematite (Fe2O3)
Mineral