Barite
Barium Sulfate (BaSO4)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Barite
Barium Sulfate (BaSO4)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
Quartzite
Quartzite (primarily SiO2)
Weathered sandstone cobble
Quartz-rich sandstone, primarily SiO₂ with clay/iron-oxide cement
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (primarily SiO2)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (mostly amorphous SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
Fossil Coral (Rugosa or Solitary Coral)
Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)
Petrified Wood / Jasper Chert
Silicified Wood / Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide, SiO2
Amber
Succinite (C10H16O)
Rainbow Obsidian
Volcanic glass (SiO2 - approximately 70% or more silicon dioxide)
Chert Nodules in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Ambergris (Geological/Organic Specimen)
Ambra grisea (Produced by Physeter macrocephalus)
Petrified Wood
Silicified Wood (SiO2)
Agatized Petrified Wood
Silicon Dioxide (SiO2) - Chalcedony pseudomorph after Wood
Quartzite
Quartzite (chiefly SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Synthetic Resin / Plastic Figurine
Synthetic Polymer (Copolymer of Polyethylene or Resin)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Fossilized Vertebra
Chordata fossil (Vertebra)
Pitted Limestone
Calcium Carbonate (CaCO3)
Green glass sphere/marble
Soda-lime glass (primarily SiO2, Na2O, CaO)
Petrified Wood
Silicified Wood (SiO2)
Pyrite Concretion
Iron Sulfide (FeS2) in Sedimentary Matrix
Fossiliferous Limestone (with Crinoids)
CaCO3 (Calcium Carbonate)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Opalite (Synthetic Opalized Glass)
Synthetic Silicon Dioxide (SiO2) glass
Obsidian
Volcanic Glass (SiO2 + impurities)
Obsidian
Volcanic Glass (predominantly SiO2)
Obsidian
Obsidian (Volcanic Glass)
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Blue faceted gemstones, likely blue sapphire
Corundum (Al₂O₃), blue varieties colored chiefly by iron and titanium