Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
Category
Browse mineraloid specimens identified by the Rock Identifier community.
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Yellow Ocher (Limonite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Obsidian
Volcanic Glass (Amorphous Silica)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Obsidian
Obsidian (Volcanic Glass)
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
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)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
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)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
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)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Mahogany Obsidian Arrowhead
Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)
Amber
Amber (Fossilized Tree Resin)
Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Slag (Industrial Glass)
Artificial Vitreous Silicate
Amber
Succinite (formula varies, primarily C10H16O)
Amber
Succinite (fossilized resin)
Amber (Burmite)
Fossilized tree resin (Succinite variant)
Amber
Succinite
Amber
Succinite (C10H16O)
Amber
Succinite
Sea Glass
Amorphous Silica (SiO2) with various additives
Pearl (in a decorative hair comb setting)
Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin
Amber
Succinite (specifically for Baltic amber; general formula C10H16O)
Amber
Succinite
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)