Rock Identifier

Category

Mineraloid

Browse mineraloid specimens identified by the Rock Identifier community.

Learn about Mineraloid in the encyclopedia

Shungite

White Beryl

Snowflake Obsidian (Flower Jasper variant) (Vitreous volcanic silicate with cristobalite inclusions) — igneous

Snowflake Obsidian (Flower Jasper variant)

Vitreous volcanic silicate with cristobalite inclusions

Mahogany Obsidian (Volcanic Glass (Silicate: SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass (Silicate: SiO2 + Fe2O3)

Obsidian (Volcanic Glass (SiO2 rich)) — Igneous

Obsidian

Volcanic Glass (SiO2 rich)

Limonite (with Pyrite) (Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O) — mineral

Limonite (with Pyrite)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Limonite (Ironstone Concretion) (Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)) — sedimentary

Limonite (Ironstone Concretion)

Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)

Pearl (Biogenic Mineral) (Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3) — mineral

Pearl (Biogenic Mineral)

Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3

Polished mahogany obsidian (Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)) — igneous

Polished mahogany obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)

Bumblebee Jasper (Calcite with Arsenic and Sulfur inclusions) — sedimentary

Bumblebee Jasper

Calcite with Arsenic and Sulfur inclusions

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Obsidian (Gold Sheen)

Obsidian (SiO2 + impurities)

Mahogany Obsidian (Volcanic Glass (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)

Mahogany Obsidian (Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)

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

Snowflake Obsidian

Volcanic Glass (SiO2) with Cristobalite inclusions

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

Obsidian

Volcanic Glass (SiO2 + impurities)

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

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)

Mahogany Obsidian (Volcanic glass (Silicon Dioxide with Hematite/Magnetite inclusions)) — igneous

Mahogany Obsidian

Volcanic glass (Silicon Dioxide with Hematite/Magnetite inclusions)

Obsidian (likely black volcanic glass) (Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition) — igneous

Obsidian (likely black volcanic glass)

Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Snowflake Obsidian (Spherulitic Volcanic Glass (SiO2 + impurities)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (SiO2 + impurities)

Obsidian (Volcanic Glass (Silica / SiO2)) — igneous

Obsidian

Volcanic Glass (Silica / SiO2)

Limonite Concretion (Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)) — sedimentary

Limonite Concretion

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

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Green Opal (Prase Opal) (SiO2 · nH2O (Hydrated Silicon Dioxide)) — mineral

Green Opal (Prase Opal)

SiO2 · nH2O (Hydrated Silicon Dioxide)

Obsidian (volcanic glass), likely black obsidian (Rhyolitic volcanic glass; predominantly amorphous SiO₂) — igneous

Obsidian (volcanic glass), likely black obsidian

Rhyolitic volcanic glass; predominantly amorphous SiO₂

Obsidian (likely black obsidian) (Volcanic glass, predominantly rhyolitic to dacitic silica-rich melt; approximate composition ~70–75% SiO₂) — igneous

Obsidian (likely black obsidian)

Volcanic glass, predominantly rhyolitic to dacitic silica-rich melt; approximate composition ~70–75% SiO₂

Black obsidian (Volcanic glass, primarily rhyolitic silica glass (SiO₂-rich, noncrystalline)) — igneous

Black obsidian

Volcanic glass, primarily rhyolitic silica glass (SiO₂-rich, noncrystalline)

Tumbled black stone, likely obsidian (Obsidian — volcanic glass, chiefly silica-rich rhyolitic composition) — igneous

Tumbled black stone, likely obsidian

Obsidian — volcanic glass, chiefly silica-rich rhyolitic composition

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

Tumbled black obsidian (likely)

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

Tumbled black stone, likely black obsidian (Obsidian — natural volcanic glass, primarily SiO₂) — igneous

Tumbled black stone, likely black obsidian

Obsidian — natural volcanic glass, primarily SiO₂

Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)) — igneous

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Mahogany Obsidian (Volcanic glass containing Magnetite/Hematite) — igneous

Mahogany Obsidian

Volcanic glass containing Magnetite/Hematite

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Obsidian (Volcanic Glass (predominantly SiO2, approximately 70% or more)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2, approximately 70% or more)

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

Snowflake Obsidian

Obsidian with Spherulitic Cristobalite (SiO2)

Mahogany Obsidian (Obsidian (SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Obsidian (SiO2 + Fe2O3)

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

Limonite (Iron Ore)

Hydrous ferric oxides (FeO(OH)·nH2O)

Limonite (Iron Ore/Sandstone mixture) (Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix) — mineral

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) — mineral

Yellow Ocher (Limonite)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Precious Coral (Red Coral) (Corallium rubrum (Calcium Carbonate, CaCO3)) — mineral

Precious Coral (Red Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Obsidian (Volcanic Glass (Amorphous Silica)) — igneous

Obsidian

Volcanic Glass (Amorphous Silica)

Opalite (Man-made Glass (Synthetic Opalized Glass)) — gemstone

Opalite

Man-made Glass (Synthetic Opalized Glass)

Black obsidian (Volcanic glass; predominantly silica-rich, noncrystalline SiO₂) — igneous

Black obsidian

Volcanic glass; predominantly silica-rich, noncrystalline SiO₂