Rock Identifier

Category

Mineraloid

Browse mineraloid specimens identified by the Rock Identifier community.

Learn about Mineraloid in the encyclopedia

Shungite

White Beryl

Black Obsidian (Volcanic Glass (SiO2)) — igneous

Black Obsidian

Volcanic Glass (SiO2)

Black Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Snowflake Obsidian (Volcanic glass containing Spherulitic Cristobalite (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulitic Cristobalite (SiO2)

Obsidian (Volcanic Glass (70-75% SiO2)) — igneous

Obsidian

Volcanic Glass (70-75% SiO2)

Mahogany Obsidian (Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Opal

Hydrated Silica (SiO2·nH2O)

Gold Sheen Obsidian (Obsidian (volcanic glass with SiO2 + gas inclusions)) — igneous

Gold Sheen Obsidian

Obsidian (volcanic glass with SiO2 + gas inclusions)

Limonite (Iron Ore) (FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

White Precious Opal (Hydrated Silica (SiO2·nH2O)) — mineral

White Precious Opal

Hydrated Silica (SiO2·nH2O)

Limonite (Hydrated Iron Oxide / Bog Iron) (FeO(OH)·nH2O) — Mineral (Sedimentary context)

Limonite (Hydrated Iron Oxide / Bog Iron)

FeO(OH)·nH2O

Mineral (Sedimentary context)

Pearl (Aragonite / Calcium Carbonate (CaCO3)) — mineral

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Black Opal Ring (Carved Opal) (Hydrated Silicon Dioxide (SiO2·nH2O)) — gemstone

Black Opal Ring (Carved Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

Opal (Precious Opal) (Hydrated Silica (SiO2·nH2O)) — mineral

Opal (Precious Opal)

Hydrated Silica (SiO2·nH2O)

Opal ring (Common opal, likely synthetic or assembled blue-green opal (hydrated amorphous silica, SiO₂·nH₂O)) — gemstone

Opal ring

Common opal, likely synthetic or assembled blue-green opal (hydrated amorphous silica, SiO₂·nH₂O)

Obsidian (likely black obsidian) (Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)) — igneous

Obsidian (likely black obsidian)

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Opalite (Man-made opalescent glass) — gemstone

Opalite

Man-made opalescent glass

Gold Sheen Obsidian (Volcanic Glass (SiO2 + impurities)) — igneous

Gold Sheen Obsidian

Volcanic Glass (SiO2 + impurities)

Obsidian (likely black obsidian) (Volcanic glass; primarily SiO₂-rich rhyolitic composition) — igneous

Obsidian (likely black obsidian)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Amber (Succinite) — mineral

Amber

Succinite

Obsidian (Amorphous volcanic glass (SiO2)) — igneous

Obsidian

Amorphous volcanic glass (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Obsidian (Obsidian (Volcanic Glass)) — Igneous

Obsidian

Obsidian (Volcanic Glass)

Snowflake Obsidian (Volcanic Glass with Spherulite Inclusions (70-75% SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (70-75% SiO2)

Limonite (Iron Ore) (Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O) — mineral

Limonite (Iron Ore)

Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O

Obsidian (black volcanic glass) (Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)) — igneous

Obsidian (black volcanic glass)

Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)

Pink opal (Common opal, hydrated amorphous silica (SiO₂·nH₂O), commonly colored by trace organic or iron compounds) — mineral

Pink opal

Common opal, hydrated amorphous silica (SiO₂·nH₂O), commonly colored by trace organic or iron compounds

Tumbled black obsidian (likely) (Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)) — igneous

Tumbled black obsidian (likely)

Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)

Obsidian (likely black volcanic glass) (Obsidian; silica-rich, noncrystalline volcanic glass, typically rhyolitic (approximately 70–75% SiO₂)) — igneous

Obsidian (likely black volcanic glass)

Obsidian; silica-rich, noncrystalline volcanic glass, typically rhyolitic (approximately 70–75% SiO₂)

Mahogany Obsidian (Volcanic Glass with Hematite inclusions) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite inclusions

Black Obsidian (Volcanic Glass (SiO2 + MgO / Fe3O4)) — igneous

Black Obsidian

Volcanic Glass (SiO2 + MgO / Fe3O4)

Black Obsidian (Volcanic Glass (SiO2)) — igneous

Black Obsidian

Volcanic Glass (SiO2)

Snowflake Obsidian (Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions) — igneous

Snowflake Obsidian

Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions

Snowflake Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)) — igneous

Snowflake Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)

Mahogany Obsidian (Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2) — igneous

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2

Obsidian (Obsidian (volcanic glass; primarily SiO2)) — igneous

Obsidian

Obsidian (volcanic glass; primarily SiO2)

Limonite (Iron-rich Siltstone / Sandstone base) (Hydrous ferric oxide mixture (FeO(OH)·nH2O)) — sedimentary

Limonite (Iron-rich Siltstone / Sandstone base)

Hydrous ferric oxide mixture (FeO(OH)·nH2O)

Obsidian (Volcanic glass (high silica volcanic rock)) — igneous

Obsidian

Volcanic glass (high silica volcanic rock)

Obsidian (Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)) — igneous

Obsidian

Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)

Black Obsidian (Obsidian (Volcanic Glass, SiO2 + impurities)) — igneous

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Snowflake Obsidian (Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)) — igneous

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)