Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Amber
Amber (C10H16O)
Obsidian
Volcanic Glass (SiO2)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Obsidian
Volcanic Glass (70-75% SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
Opal
Hydrated Silica (SiO2·nH2O)
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Black Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Obsidian
Obsidian (Volcanic Glass)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Obsidian
Volcanic Glass (SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Glass
Amorphous Silicon Dioxide (SiO2)
Amber with Organic Inclusions
Succinite (fossilized resin)
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
Amber
Succinite (organic mineraloid); Chemical formula: C10H16O
Limonite (Iron Ore Congcretion)
Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Obsidian
Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)
Obsidian
Volcanic glass (high silica volcanic rock)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Amorphous volcanic glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Amber
Succinite (C10H16O)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Obsidian
Volcanic glass
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)