Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Category
Organic Gemstone (Not A Rock)
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock) in the encyclopedia
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Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
mineral
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Likely bituminous coal
Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image
sedimentary
Druzy quartz on matrix
Quartz (SiO₂), microcrystalline crystal coating
mineral
Tahitian Pearl (Black / Pistachio Pearl)
Biogenic Aragonite / Calcite (CaCO3 with conchiolin)
gemstone
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
sedimentary
Fossilized Shell Fragment
Invertebrate marine fossil, likely calcium carbonate replacement
fossil
Green Moss Agate
Silicon Dioxide (SiO2) with Mineral Inclusions
sedimentary
Turquoise
Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Polished red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Tumbled red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Synthetic Wolf Plush (Non-mineral)
Canis lupus similis (Prop material: Polyester & Synthetic fibers)
Synthetic material/Textile
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin
gemstone
Chert (Yellow/Tan)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Silicon dioxide (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
sedimentary
Tumbled brown agate (likely moss or plume agate)
Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possibly mineral inclusions
gemstone
Petrified Wood
Silicified Wood (SiO2)
mineral
Chert / Flint
Cryptocrystalline Quartz (SiO2)
sedimentary
Lapis Lazuli (Low Grade)
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2)
metamorphic
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
sedimentary
Fossil bivalve shell
Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features
fossil
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinates (fossilized tree resin), approximately C10H16O
organic gemstone
Polished moss agate (likely dendritic agate)
Chalcedony, microcrystalline quartz (SiO₂), with inclusions of manganese/iron oxides or hornblende
gemstone
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (likely chalcedony-rich flint)
Microcrystalline quartz, SiO₂ (quartz/chalcedony)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
metamorphic
Red-and-green jasper
Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides and possibly chlorite/epidote
mineral
Pearl
Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)
gemstone
Pearl
Calcium carbonate (CaCO3) + organic conchiolin
gemstone
Coal (Bituminous / Anthracite)
Organic Sedimentary Rock (Carbonaceous Rock)
sedimentary
Coal
Coal (Sedimentary Rock / Organic Rock)
sedimentary
Amber (in Matrix/Shale)
Amber (Fossilized Tree Resin)
mineral
Amber
Succinite (organic gemstone, approx. C10H16O)
fossil
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
mineral
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Organic gemstone / Sedimentary mineraloid
Chert (Arrowhead/Artifact Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary