Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Chert (Flint variety)
Silicon Dioxide (SiO2)
Chert (specifically Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Chert (Microcrystalline Quartz, SiO2)
Chert (and Limestone)
Silicon Dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Obsidian
Obsidian (Volcanic glass), SiO2 (major component)
Baroque Pearl (and potentially a small Sapphire/Blue Topaz)
Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.
Asphalt (Aggregate)
Bituminous macadam / Concrete Aggregate
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide SiO2)
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
Obsidian with Mahogany Phasing
Volcanic Glass (SiO2 + Fe2O3)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Oak-grain Laminate (Industrial/Decorative Furniture Finish)
Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)
Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
Obsidian
Volcanic Glass (predominantly SiO2)
Obsidian
Volcanic Glass (SiO2 + impurities)
Quartzite
Quartzite (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Synthetic Resin / Plastic Figurine
Synthetic Polymer (Copolymer of Polyethylene or Resin)
Obsidian (Black Obsidian)
Amorphous volcanic glass (primarily SiO2)
Conglomerate
Conglomerate (SiO2, Al2O3, Fe2O3, CaCo3)
Ferrosilicon Slag (Industrial Vitrified Glass)
Vitreous Silicate Residue
Grey River Stone (Quartz-rich Quartzite/Siltstone)
Quartzite / Meta-siltstone (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
River Pebble (Greywacke or Quartzite-rich Sandstone)
Lithic Sandstone (primarily SiO2 with rock fragments)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Chert (varieties: Flint or Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Yellow or Brown Jasper)
Microcrystalline Quartz (SiO2)