Obsidian
Obsidian (Volcanic Glass)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Limonite (Iron Stone/Ocher)
Limonite (FeO(OH)·nH2O)
Obsidian
Amorphous volcanic glass (primarily SiO2)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Black Obsidian
Obsidian (Amorphous Silicon Dioxide)
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Fulgurite
Lechatelierite
Opal
Hydrated amorphous silica (SiO2·nH2O)
Opal
Hydrated amorphous silica (SiO2·nH2O)
Black Opal (Kalimaya)
Hydrated Silica (SiO2·nH2O)
Opal
Hydrated silica (SiO2 · nH2O)
Amber
Fossilized Tree Resin (Succinite)
Common Green Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Bumblebee Jasper
Anhydrite-Aragonite mixture with Orpiment and Realgar
Opalite
Synthetic glass (SiO2 + metal additions)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
Amber (Baltic)
Succinith (Fossilized Tree Resin)
Cobalt Glass Slug (Cullet)
Man-made Silicate Glass with Cobalt Oxide (CoO)
Leland Blue Stone
Anthropogenic Iron Smelting Slag
Opal
Hydrated Silica (SiO2·nH2O)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial byproduct)
Fulgurite
Lechatelierite (Silica glass), typically SiO2
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
Fulgurite
Luechatelierite (SiO2 glass)
Libyan Desert Glass
Natural Silica Glass (SiO2 with minor iron and titanium)
Amber
Succinite
Tektite (Indochinite)
Tektite (High-silica impact glass)
Boulder Opal
Hydrated Silica (SiO2·nH2O)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Byproduct)
Blue Opal Inlay (Simulated/Lab-created)
Hydrated Amorphous Silica (SiO2·nH2O) with polymer resin
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
Tektite
Tektite (high-silica natural glass)
Precious Opal
Hydrated silica (SiO2·nH2O)
Black Opal
Hydrated Silica (SiO2·nH2O)
Glass
Amorphous Silicon Dioxide (SiO2)