Rock Identifier

Category

Organic Mineraloid

Browse organic mineraloid specimens identified by the Rock Identifier community.

Learn about Organic Mineraloid in the encyclopedia

Shungite

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Jet

Oil Shale

Peat

Pearl

Lizard Skin Jasper

Opalized Wood

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

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

Obsidian (Volcanic Glass (felsic composition)) — igneous

Obsidian

Volcanic Glass (felsic composition)

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

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

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

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)

Obsidian (Volcanic Glass (Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic Glass (Silicon Dioxide with impurities)

Obsidian (Obsidian (Amorphous volcanic glass, SiO2 with impurities)) — igneous

Obsidian

Obsidian (Amorphous volcanic glass, SiO2 with impurities)

Snowflake Obsidian (Volcanic glass containing Spherulites (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulites (SiO2)

Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — Mineral

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Baltic Amber (Butterscotch variety) (Succinite) — Organic Gemstone/Mineraloid

Baltic Amber (Butterscotch variety)

Succinite

Organic Gemstone/Mineraloid

Baltic Amber (Butterscotch or Egg Yolk Variety) (Succinite (C10H16O)) — Organic Gemstone (Mineraloid)

Baltic Amber (Butterscotch or Egg Yolk Variety)

Succinite (C10H16O)

Organic Gemstone (Mineraloid)

Obsidian (black volcanic glass) (Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides) — igneous

Obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

Likely obsidian (rough fragment) (Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)) — igneous

Likely obsidian (rough fragment)

Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)

Obsidian (Volcanic Glass (Amorphous SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous SiO2)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Common Opal with Host Rock (Opal (Hydrated silica, SiO2·nH2O)) — mineral

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

Mahogany Obsidian (Obsidian (volcanic glass with hematite/magnetite inclusions)) — igneous

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

Precious Opal (Hydrated Silicon Dioxide (SiO2·nH2O)) — gemstone

Precious Opal

Hydrated Silicon Dioxide (SiO2·nH2O)

Limonite (Ironstone) Concretion (FeO(OH)·nH2O (Hydrous ferric oxide)) — sedimentary

Limonite (Ironstone) Concretion

FeO(OH)·nH2O (Hydrous ferric oxide)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Snowflake Obsidian (Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)

Obsidian (Black Obsidian) (Obsidian (Volcanic Glass)) — igneous

Obsidian (Black Obsidian)

Obsidian (Volcanic Glass)

Limonite (Yellow Ochre) (Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)) — mineral

Limonite (Yellow Ochre)

Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)