Obsidian
Volcanic Glass (SiO2)
Category
Browse mineraloid specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Opal
Hydrated amorphous silica (SiO2·nH2O)
Green Opal
Hydrated Silica (SiO2·nH2O)
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
Opal
Hydrated Silica (SiO2·nH2O)
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Black Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Amber
Succinite (Resinite)
Amber with Organic Inclusions
Succinite (fossilized resin)
Amber with Inclusion
Succiniferous fossil resin (C10H16O)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Green Opal
Hydrated amorphous silica (SiO2·nH2O) with inclusions
Amber (Copal)
Succinate (Fossilized Resin)
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Opalite
Synthetic Glass (Amorphized Silicon Dioxide)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Amber
Succinite (fossilized resin)
Amber
Succinite (Fossilized Tree Resin)
Amber
Succinite (fossilized tree resin)
Amber
Succinite (approximate formula C10H16O)
Amber
Succinrite (Organic Gemstone)
Amber
Succinite (a fossilized organic resin containing succinic acid)
Tektite (Indochinite)
Impact Glass (SiO2 + Al2O3)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Shungite
Carbonaceous rock (primarily amorphous carbon)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
Amber
Amber (Succinite), fossilized tree resin
Amber
Succinite (fossilized resin); C10H16O
Amber / Copal
Succinite (fossilized tree resin)
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Succinite