Limonite (Iron Stone/Goethite)
Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))
Category
Browse organic mineraloid and mineral specimens identified by the Rock Identifier community.
Limonite (Iron Stone/Goethite)
Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))
Mahogany Obsidian
Volcanic Glass with Hematite (SiO2 + Fe2O3)
Green Opal or Yellow Opal
Hydrated Silica (SiO2·nH2O)
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
Limonite (Iron Ore Congcretion)
Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions
Black Obsidian
Volcanic Glass (SiO2 + MgO / Fe3O4)
Black Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2
Obsidian
Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)
Obsidian
Volcanic glass (high silica volcanic rock)
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Polished black obsidian pyramid/block
Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)
Tumbled mahogany obsidian
Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions
Black Obsidian
Amorphous volcanic glass (SiO2)
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic glass
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Limonite (Ironstone Concretion)
Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
White Opal
Hydrated Silica (SiO2·nH2O)
Obsidian
Volcanic Glass (SiO2 rich)
Polished mahogany obsidian (likely)
Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite/Magnetite inclusions)
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite inclusions)
Gold Sheen Obsidian
Volcanic Glass (SiO2 + impurities)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (primarily SiO2)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass, SiO2)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
Black Obsidian
Obsidian (Volcanic Glass, ~70% SiO2)
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin