Obsidian
Volcanic Glass (SiO2 + impurities)
Category
Browse sedimentary (or mineraloid) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2 + impurities)
Pearl (Biogenic Mineraloid)
Calcium carbonate (Aragonite) and Conchiolin, CaCO3
Amber
Succinite (formula varies, primarily C10H16O)
Amber
Succinite (fossilized resin)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
Obsidian
Volcanic Glass (SiO2)
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
Obsidian
Volcanic Glass (SiO2 rich)
Amber
Succinite (Fossilized Tree Resin), C10H16O
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
Obsidian
Volcanic Glass (predominantly SiO2)
Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
Amber
Succinite (with a generalized formula of C10H16O)
Obsidian
Volcanic Glass (Amorphous Silica)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Obsidian
Obsidian (Volcanic Glass)
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Amber
Amber (Fossilized Tree Resin)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Extrusive Volcanic Glass)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
Tektite (likely Australite)
Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)