Shale
Shale (comprised mostly of clay minerals and quartz)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Shale
Shale (comprised mostly of clay minerals and quartz)
Fossiliferous Limestone
Limestone with embedded fossil cross-section
Coal (Bituminous or Anthracite)
Carbonaceous Sedimentary Rock
Lapis Lazuli
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Amber
Succinite / Fossilized Tree Resin
Chert / Flint
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Chert (Flint)
SiO2 (Microcrystalline Quartz)
Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Pyrite in Shale
Iron Disulfide (FeS2)
Sedimentary Sandstone
Arenite (Sedimentary Rock)
Jasper
Microcrystalline Quartz (SiO2)
Moss-covered Limestone with Quartz/Calcite Pocket
Calcium Carbonate (CaCO3) rock with biological moss coating
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
Amber (Copal)
Succinite (fossilized tree resin)
Picture Jasper
SiO2
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
Probable amber fragment
Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)
Amber
Succinate (Organic Fossilized Resin)
Freshwater Pearl
Calcium Carbonate (CaCO3) in the form of Aragonite and Calcite
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Chert Nodules or Concretion
Cryptocrystalline Quartz (SiO2)
River Pebble (Siltstone/Mudstone)
Clastic sedimentary rock
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite
Sandstone
Arenite
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Limestone (Tufa/Travertine)
Sedimentary Calcium Carbonate (CaCO3)
Amber
Fossilized Tree Resin (C10H16O)
Anthracite Coal
Anthracite (a variety of coal, predominantly carbon)
Fossilized Bone
Permineralized Vertebrate Bone
Limestone with Lichen
Calcium Carbonate (CaCO3) with Endolithic/Epilithic Lichen
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
Amber
Succinate (Fossilized Tree Resin)
Amber
Fossilized Tree Resin
Limestone
Sedimentary Rock (Primarily CaCO3)
Red Jasper
Silicon Dioxide (SiO2)
Sandstone
Sandstone (SiO2-dominated clastic rock)
Jasper
Silicon dioxide (Microcrystalline quartz, SiO2)