Shale or Slaty Mudstone
Argillaceous sedimentary rock
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Red Coral (with Hematite and Black Pearl accents)
Corallium rubrum (Calcium Carbonate, CaCO3)
White Coral
Corallium rubrum (biocarbonate calcium) / CaCO3
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Amber
Succinite (a fossilized organic resin)
Pearl
Calcium Carbonate (CaCO3) + Conchiolin
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
Amber
Organic gemstone (Succinite is common if from the Baltic)
Amber
Succinite (Approximate formula: C10H16O)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
Amber
Succinite (fossilized resin)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
Sandstone
Arenite
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Amber
Succinite
Shale
Fissile Mudstone (Shale)
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (Iron-stained)
Chert (SiO2)
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
Pearl (incorporated into jewelry)
Aragonite and Calcite (CaCO3)
Pyrite in Shale
Iron Disulfide (FeS2)
Chert (specifically Flint or Jasper variant)
Cryptocrystalline Quartz (SiO2)
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Precious Red Coral
Corallium rubrum / Corallium japonicum
Pearl
Calcium carbonate (CaCO3) in the form of Aragonite or Calcite
Pearl
Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3
Amber
Succinite (fossilized tree resin), C10H16O
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Amber
Succinite (fossilized resin)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Green variety)
Microcrystalline Opaline/Quartz (SiO2)
Shale
Shale (comprised mostly of clay minerals and quartz)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)