Obsidian
Obsidian (Volcanic Glass)
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Amber with Organic Inclusions
Succinite (fossilized resin)
Amber
Succinite (organic mineraloid); Chemical formula: C10H16O
Amber
Succinates
Obsidian
Volcanic Glass (SiO2)
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
Opal
Hydrated Silica (SiO2·nH2O)
Polished mahogany obsidian
Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)
Polished mahogany obsidian
Volcanic glass; predominantly silica-rich rhyolitic composition (SiO₂)
Polished black obsidian
Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)
Black Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Obsidian
Volcanic Glass (70-75% SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
Obsidian
Volcanic Glass (SiO2)
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Glass
Amorphous Silicon Dioxide (SiO2)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Amber
Succinite
Amber
Succinite (Organic Mineraloid) - C10H16O
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
Amber
Succinite (C10H16O)
Opal ring
Common opal, likely synthetic or assembled blue-green opal (hydrated amorphous silica, SiO₂·nH₂O)
Obsidian (likely black obsidian)
Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)
Obsidian (likely black obsidian)
Volcanic glass; primarily SiO₂-rich rhyolitic composition
Obsidian
Amorphous volcanic glass (SiO2)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
Pink opal
Common opal, hydrated amorphous silica (SiO₂·nH₂O), commonly colored by trace organic or iron compounds
Limonite (Iron Ore Congcretion)
Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Green Opal or Yellow Opal
Hydrated Silica (SiO2·nH2O)
Mahogany Obsidian
Volcanic Glass with Hematite (SiO2 + Fe2O3)
Obsidian
Volcanic glass
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Obsidian (black volcanic glass)
Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)
Tumbled black obsidian (likely)
Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)
Obsidian (likely black volcanic glass)
Obsidian; silica-rich, noncrystalline volcanic glass, typically rhyolitic (approximately 70–75% SiO₂)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions
Black Obsidian
Volcanic Glass (SiO2 + MgO / Fe3O4)
Black Obsidian
Volcanic Glass (SiO2)