Mahogany Obsidian
Volcanic glass (high silica) with inclusions of Magnetite or Hematite
Category
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
Mahogany Obsidian
Volcanic glass (high silica) with inclusions of Magnetite or Hematite
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)
Polished mahogany obsidian (probable)
Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Obsidian
Volcanic Glass (SiO2 rich)
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
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)
Likely obsidian (possibly tektite or slag glass)
Volcanic glass; primarily SiO₂, noncrystalline
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Limonite (Iron Stone/Ocher)
Limonite (FeO(OH)·nH2O)
Black Obsidian
Volcanic Glass (SiO2 + impurities like Fe3O4)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Snowflake Obsidian
Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Amber
Amber (C10H16O)
Obsidian
Volcanic Glass (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Amorphous volcanic glass (primarily SiO2)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Black Obsidian
Obsidian (Amorphous Silicon Dioxide)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)