Obsidian
Volcanic Glass
Category
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass
Obsidian
Volcanic glass (SiO2 + impurities)
Obsidian
Volcanic Glass
Limonite or Ironstone Nodule
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Black Obsidian
Volcanic Glass (predominantly SiO2)
Mahogany Obsidian Arrowhead
Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)
Black Obsidian
Volcanic Glass (Amorphous SiO2 with trace impurities)
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass (Amorphous silicon dioxide with impurities)
Black Obsidian
Volcanic glass
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass (SiO2 + impurities)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Obsidian
Volcanic Glass
Tumbled black stone, likely black obsidian
Obsidian — volcanic glass, primarily SiO₂
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
Amber
Succinite (specifically for Baltic amber; general formula C10H16O)
Mahogany Obsidian
Volcanic glass (high silica) with inclusions of Magnetite or Hematite
Amber
Succinite (specifically for Baltic amber); Approximate formula: C10H16O
Limonite (Ironstone)
Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Volcanic Glass (Amorphous SiO2)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Obsidian
Volcanic Glass (SiO2 rich)
Polished mahogany obsidian (probable)
Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Black Obsidian
Volcanic Glass (Amorphous SiO2)
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass
Obsidian
Volcanic Glass (70% or more SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Amber in Matrix
Succinite (Carbon-based organic polymer)
Obsidian
Obsidian (Amorphous volcanic glass, predominantly SiO2)
Obsidian
Volcanic glass
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Amber
Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Likely obsidian (possibly tektite or slag glass)
Volcanic glass; primarily SiO₂, noncrystalline
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)