Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
Petrified Wood
Silicified Paleoxylon (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
Polished banded agate (likely picture jasper or petrified wood)
Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions
Red Jasper
Quartz (SiO2) with iron oxide inclusions
Chert (Flint)
Chert (Microcrystalline Silica, SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Flint/Jasper)
Microcrystalline Quartz (SiO2)
Cultured pearls
Pearl; predominantly aragonite (CaCO₃) in nacre with organic conchiolin
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Amber
Fossilized Tree Resin (C10H16O)
Chert (specifically Flint or Jasper variant)
Microcrystalline silica (SiO2)
Chert Nodule
Microcrystalline Silica (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Petrified Wood
Silicified Wood (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Chert (specifically Flint or Novaculite variant)
Chert (Microcrystalline Quartz, SiO2)
Amber (likely Baltic amber)
Fossilized tree resin; chiefly polymerized diterpenoid resin (succinite)
Raw amber
Amber (fossilized plant resin; commonly succinite, C10H16O)
Amber
Fossilized Tree Resin
Pearl
Pearl; chiefly aragonite (CaCO₃) with conchiolin
Polished fossil bone fragment
Fossilized bone, likely mammalian or reptilian; exact taxon cannot be determined from the image
Chert (variations include Flint)
Sedimentary cryptocrystalline quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Polished amber
Amber (fossilized plant resin; primarily organic polymerized terpenes)
Petrified Wood
Silicified Wood (SiO2)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Pearl necklace (likely cultured pearls)
Pearl; chiefly aragonite (CaCO₃) in an organic conchiolin matrix
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)