Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Category
Browse mineraloid (impact glass) specimens identified by the Rock Identifier community.
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Polished mahogany obsidian (likely)
Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Obsidian (Volcanic Glass, ~70% SiO2)
Obsidian
Volcanic glass (high silica volcanic rock)
Obsidian
Volcanic Glass (SiO2 + impurities)
Obsidian
Volcanic Glass (Silica / SiO2)
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite inclusions)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Obsidian
Obsidian (Volcanic Glass)
Tumbled mahogany obsidian
Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Obsidian
Volcanic Glass (Amorphous Silica)
Obsidian
Volcanic glass
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Quartzite (River-worn Shiner)
Quartzite (Formula: SiO2)
Shungite
Shungite (carbon-rich Precambrian mineraloid)
Obsidian
Obsidian (Volcanic Glass)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Volcanic Glass (felsic composition)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
Precious Coral (Red Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Obsidian
Volcanic Glass (Amorphous SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Tumbled black stone, likely black obsidian
Obsidian — natural volcanic glass, primarily SiO₂
Amethyst (Water-Worn Pebble)
Silicon Dioxide (SiO2 with iron impurities)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Amber
Succinite (with a generalized formula of C10H16O)
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
Black Obsidian
Volcanic glass (Amorphous silicates)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
Mahogany Obsidian
Volcanic Glass (SiO2 with Fe/Mg oxides)