Obsidian
Obsidian (Volcanic Glass)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Chert (and Fossilized Brachiopod shell)
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert / Flint
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Iron-stained)
Chert (primarily Microcrystalline Quartz, SiO2)
Chert (Red/Pink Jasper subtype)
Silicon Dioxide (SiO2)
Obsidian (worked into an arrowhead profile)
Obsidian (volcanic glass), primarily SiO2 (Silicon Dioxide)
Opalite
Man-made Synthetic Glass (Silicon Dioxide with metal additives)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified wood (Quartz variant, SiO2)
Obsidian Arrowhead
Volcanic Glass (Primary composition: SiO2)
Snowflake Obsidian
Obsidian (volcanic glass) with Cristobalite inclusions
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)
Pyrite in Shale
Iron Sulfide (FeS2) in Argillaceous Shale
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Obsidian
Obsidian (Volcanic Glass)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂)
Obsidian
Volcanic Glass (Primary component: SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
Pyrite
Pyrite (FeS2)
Note: Item is a Synthetic/Man-made Object
Titanium-coated Stainless Steel (Fe-Cr-Ni-Ti)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Quartz Geode
Silicon Dioxide (SiO2)
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
Quartzite
Quartzite (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Geode (Unopened)
Silica-rich concretion (SiO2)
Obsidian
Volcanic Glass (SiO2, usually 70% or more)
Quartzite
Quartzite (SiO2)
Black Obsidian with white veins
Volcanic Glass (70–75% SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Graphite Schist
C (Carbonaceous Schist)
Chert (specifically Gray/Blue Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Black Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
Mixed Quartz and Jasper Pebbles
Silicon Dioxide (SiO2)