Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
Amazonite
K(AlSi3O8) - Microcline variant
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
Prehnite
Prehnite, Ca2Al(AlSi3O10)(OH)2
Pyrite-bearing sulfide ore, possibly pyrrhotite-rich
Pyrite (FeS₂) with likely pyrrhotite (Fe₁₋ₓS), within a dark sulfide-rich host rock
Amber cabochon pendant
Amber (fossilized tree resin; chiefly polymerized terpenoids)
Imitation or Cultured Pearl Earrings
Calcium carbonate (CaCO3) or synthetic polymer/glass
Pyrite
Iron Disulfide (FeS2)
Precious Coral (Red Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Amber
Amber (C10H16O)
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
Amber
Fossilized tree resin (Amorphous organic polymer)
Chert (and Flint)
Silicon Dioxide (SiO2)
Yellow Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions
Chrysoprase-bearing serpentine (probable)
Serpentine-group minerals, mainly lizardite/antigorite, with possible nickel-bearing chrysoprase or green garnierite
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Chert (Jasper/Chalcedony)
Microcrystalline Silica (SiO2)
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
Green Fluorite
Calcium Fluoride (CaF2)
Chert (Banded Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Pearl (Pendant)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Herkimer Diamond
Quartz (Silica - SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron inclusions
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with impurities
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow Jasper/Flint)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Chrysocolla Chalcedony
Hydrated Copper Phyllosilicate (Cu,Al)2H2Si2O5(OH)4 + SiO2
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
Turquoise
Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
Petrified Wood
Silicified Wood (SiO2 permineralization)
Turquoise
Hydrous phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Chert (including Flint and Jasper variants)
Microcrystalline or Cryptocrystalline Quartz (SiO2)