Weathered chert or silicified limestone
Microcrystalline quartz (SiO₂), likely chert formed by silicification of carbonate rock
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Weathered chert or silicified limestone
Microcrystalline quartz (SiO₂), likely chert formed by silicification of carbonate rock
Chert (Black Flint)
Silicon Dioxide (SiO2)
Fossiliferous Shale
Carbonaceous Shale (with potential plant/aquatic fossils)
Iron-rich meteorite fragment (probable)
Unclassified meteoritic iron–nickel or stony-iron fragment
Iron-rich meteorite candidate
Undetermined; possible stony-iron or iron meteorite, commonly kamacite–taenite (Fe–Ni)
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Garden Quartz (Lodolite / Inclusion Quartz)
Quartz with inclusions (SiO2 with various mineral inclusions)
Amber
Resinite (Succinite if from the Baltic); Chemical Formula: C10H16O (approximate)
Amber
Succinite (approximate formula C10H16O)
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Chert Pebble
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Chert (Jasper/Chalcedony mix)
Microcrystalline Quartz (SiO2)
Fossilized Bone
Vertebrate fossil (mineralized bone)
Chert (Chalky/Gray Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Iron-rich meteorite candidate
Unclassified stony-iron or iron meteorite fragment
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
Black Limestone
Bituminous Limestone (Calcium Carbonate - CaCO3)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Pearl
Calcium carbonate (CaCO3) in the form of Aragonite or Calcite
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Chert (Flint nodule)
Chert (SiO2)
Amber
Succinite
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sedimentary Rock (Limestone or Siltstone pebble)
Sedimentary rock fragment
Mixed Gemstone and Mineral Collection
Silicon Dioxide (SiO2) based minerals and others
Pyritic Shale
Carbonaceous Shale with Iron Pyrite (FeS2)
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Likely bituminous coal
Coal, predominantly carbon-rich organic matter with variable maceral and mineral content
Pearl (incorporated into jewelry)
Aragonite and Calcite (CaCO3)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Fossilized Wood / Petrified Wood
Petrified Wood (Silicified Flora)
Quartz-rich breccia or silicified breccia
Cryptocrystalline quartz/chalcedony (SiO₂) with iron oxides and dark lithic fragments; exact classification is uncertain from the photograph
Chert (variations include Flint/Jasper)
Cryptocrystalline Quartz (SiO2)
Amber
Succinite (Fossilized Resin)
Amber
Succinited (fossilized tree resin)
Amber
Succinite / Fossilized Resin (C10H16O)
Amber
Succinite
Amber
Fossilized Tree Resin
Translucent amber-colored gemstone, likely citrine or amber
Most plausibly quartz (SiO₂), specifically citrine; amber would be fossilized resin (organic polymer)
Polished amber-like organic gemstone
Likely amber (fossilized plant resin), possibly copal or brown chalcedony; exact identification requires testing
Polished amber-like organic gemstone
Amber (fossilized tree resin), commonly succinite; exact identification is uncertain from the image