Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Category
Browse mineraloid (impact glass) specimens identified by the Rock Identifier community.
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Amber
Succinite (fossilized tree resin)
Baltic Amber
Succinite (Polmerized conifer resin)
Amber
Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
Obsidian
Volcanic Glass (SiO2 + impurities)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Obsidian
Volcanic Glass (SiO2 rich)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
Obsidian
Volcanic Glass (Amorphous Silica)
Obsidian
Obsidian (Volcanic Glass)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Shungite
Shungite (carbon-rich Precambrian mineraloid)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Amber
Succinite (with a generalized formula of C10H16O)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Obsidian
Obsidian (volcanic glass)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Opalite (Synthetic Moonstone/Opal)
Synthetic Silica Glass
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
Slag
Ferrous slag (by-product of iron smelting)
Sea Glass
Amorphous Silica (SiO2) with various additives
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Man-made Glass (Tumbled/Shaped)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Opalite
Synthetic Opalised Glass
Mahogany Obsidian Arrowhead
Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)