Chert
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (mineraloid) specimens identified by the Rock Identifier community.
Chert
Microcrystalline Quartz (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Black Chert/Flint)
Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (principally SiO2)
Raw amber
Fossilized tree resin; primarily polymerized terpenoid resin (succinite when Baltic-type)
Carved red coral bead (likely coral or coral-colored resin)
Corallium spp. (precious coral; calcium carbonate, CaCO₃)
Chert (Black Chert/Flint)
Silicon Dioxide (SiO2)
Chert (specifically Flint)
Silicon Dioxide (SiO2)
Black Jasper
Silicon Dioxide (SiO2) with impurities
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Likely amber or amber-like resin fragment
Amber (fossilized plant resin), commonly succinite; identification uncertain from the image
Moss Agate
SiO2 (Cryptocrystalline Quartz)
Polished amber-like agate or jasper carving
Likely chalcedony (microcrystalline SiO₂), possibly iron-stained carnelian/jasper; exact identification requires testing
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
Pearl oyster shell with cultured pearls
Mollusk shell (likely Pinctada spp.) containing aragonite pearls, CaCO₃
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
Dyed Pink Quartzite (Jadeite Simulant)
Silicon Dioxide (SiO2) with organic dye
Red coral beads
Precious coral, commonly Corallium rubrum (calcium-carbonate skeleton)
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Polished amber-colored translucent stone, likely citrine or yellow chalcedony
Most consistent with quartz (SiO₂), potentially citrine; translucent yellow chalcedony is another possibility
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH)
Chert (Flint)
Microcrystalline Opaline Silica (SiO2)
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) / Microcrystalline Quartz
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Angel Skin Coral
Corallium rubrum / Corallium spp. (Calcium Carbonate, CaCO3)
Chalcopyrite
CuFeS2
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline silica (SiO2)
Chert Nodule
Microcrystalline Silica (SiO2)
Chert (Flint)
Chert (Microcrystalline Silica, SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Flint/Jasper)
Microcrystalline Quartz (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions