Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Category
Browse mineraloid (organic) specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Glass
Amorphous Silicon Dioxide (SiO2)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
Fulgurite
Lechatelierite (Silica glass), typically SiO2
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
Fulgurite
Luechatelierite (SiO2 glass)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Byproduct)
Blue Opal Inlay (Simulated/Lab-created)
Hydrated Amorphous Silica (SiO2·nH2O) with polymer resin
Amber
Succinite
Libyan Desert Glass
Natural Silica Glass (SiO2 with minor iron and titanium)
Tektite (Indochinite)
Tektite (High-silica impact glass)
Black Opal
Hydrated Silica (SiO2·nH2O)
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
Tektite (Indochinite)
Tektite - High-silica amorphous glass (SiO2 + Al2O3)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
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)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Limonite (Iron Ore Congcretion)
Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Opalite
Synthetic Glass (Amorphized Silicon Dioxide)
Conch Pearl
Calcareous concretion (CaCO3)
Sea Glass (Frosted Quartz/Glass)
Amorphous Silicon Dioxide (SiO2)
Amber
Succinite (approximate formula C10H16O)
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
Black Opal
Hydrated silica (SiO2·nH2O)
Fulgurite
Liesegang (Fulgurite)
Amber
Succinite (C10H16O)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Opal
Hydrated silica (SiO2·nH2O)