Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Category
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
Green Moss Agate
Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
Petrified Wood
Silicified Wood (SiO2)
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Succinite (specifically for Baltic amber; fossilized tree resin)
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
Amber
Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)
Limestone
Calcium Carbonate (CaCO3)
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
Amber
Succinite (fossilized tree resin, C10H16O)
Amber
Fossilized Tree Resin
Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Amber (Raw Copal)
Fossilized Plant Resin (Gummite/Succinite)
Chert with Quartz Vein
Microcrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe oxides)
Petrified Wood
Silicified Wood (primarily SiO2)
Pyrite in Shale
Iron Sulfide (FeS2) in Argillaceous Shale
Pink Opal
Hydrated Silica (SiO2·nH2O)
Amber
Succinite (fossilized tree resin)
River Cobble (Sandstone)
Arenite (primarily SiO2)
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Amber
Succinite
Moss Agate with Quartz Druzy
Chalcedony with inclusions (SiO2)
Liesegang Ring Siltstone
Siltstone with iron oxide Liesegang bands
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mg/Mn/Chlorite)
Amber
Succinite (C10H16O)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) - Limestone
Limestone pebble
Sedimentary rock composed mainly of calcium carbonate (CaCO3)
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2), Microcrystalline Quartz
Jasper
Silicon dioxide (SiO2)
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
Mosasaur Tooth
Mosasaurus sp.