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 arrowhead (Volcanic glass; predominantly SiO₂, with minor feldspar, pyroxene, and iron oxides) — igneous

Obsidian arrowhead

Volcanic glass; predominantly SiO₂, with minor feldspar, pyroxene, and iron oxides

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

Mahogany Obsidian

Volcanic Glass with Hematite (SiO2 + Fe2O3)

Black Obsidian (Volcanic Glass (SiO2 + impurities like Fe3O4)) — igneous

Black Obsidian

Volcanic Glass (SiO2 + impurities like Fe3O4)

Opal (Hydrated silica (SiO2 "NH2O)) — mineraloid

Opal

Hydrated silica (SiO2 "NH2O)

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

Snowflake Obsidian

Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

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

Snowflake Obsidian

Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Opal (Hydrated amorphous silica (SiO2·nH2O)) — mineral

Opal

Hydrated amorphous silica (SiO2·nH2O)

Black obsidian (likely) (Volcanic glass; primarily silica-rich, noncrystalline SiO₂ composition) — igneous

Black obsidian (likely)

Volcanic glass; primarily silica-rich, noncrystalline SiO₂ composition

Polished black stone, likely black obsidian (Obsidian (volcanic glass), primarily rhyolitic silica glass) — igneous

Polished black stone, likely black obsidian

Obsidian (volcanic glass), primarily rhyolitic silica glass

Obsidian (Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)) — igneous

Obsidian

Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)

Obsidian (Volcanic glass (mainly SiO2 with inclusions)) — igneous

Obsidian

Volcanic glass (mainly SiO2 with inclusions)

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

Mahogany Obsidian

Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Limonite (Iron Stone/Ocher) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (Iron Stone/Ocher)

Limonite (FeO(OH)·nH2O)

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

Obsidian

Amorphous volcanic glass (primarily SiO2)

Limonite/Goethite on Shale (Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock) — sedimentary

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

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

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

Snowflake Obsidian (Volcanic Glass with Cristobalite inclusions (70–75% SiO2)) — Igneous

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions (70–75% SiO2)

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

Black Obsidian

Obsidian (Amorphous Silicon Dioxide)

Snowflake Obsidian (Volcanic Glass with Cristobalite Inclusions) — igneous

Snowflake Obsidian

Volcanic Glass with Cristobalite Inclusions

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

Precious Opal

SiO2·nH2O (Hydrated Silicon Dioxide)

Amber (Succinite (fossilized tree resin)) — mineraloid / sedimentary organic material

Amber

Succinite (fossilized tree resin)

mineraloid / sedimentary organic material

Common Opal in Host Rock (Hydrated Silica (SiO2·nH2O)) — mineraloid

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Common Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — mineraloid

Common Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

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

Black Obsidian

Obsidian (Volcanic Glass, SiO2+)

Snowflake Obsidian (Spherulitic Volcanic Glass (primarily SiO2)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Limonite (Yellow Ochre) (Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)) — mineral

Limonite (Yellow Ochre)

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

Black Obsidian (Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)) — igneous

Black Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Limonite (Yellow Ochre) (Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)) — mineral

Limonite (Yellow Ochre)

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

Limonite/Goethite Concretion (Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)) — sedimentary

Limonite/Goethite Concretion

Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Limonite (Ironstone) (Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)) — mineral

Limonite (Ironstone)

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

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

Limonite (Iron Ore)

Limonite (Hydrated iron oxide - FeO(OH)·nH2O)

Green Opal or Yellow Opal (Hydrated Silica (SiO2·nH2O)) — mineraloid

Green Opal or Yellow Opal

Hydrated Silica (SiO2·nH2O)

Green Opal (Hydrated amorphous silica (SiO2·nH2O) with inclusions) — mineraloid

Green Opal

Hydrated amorphous silica (SiO2·nH2O) with inclusions

Cobalt Glass Slug (Man-made Glass) (Amorphous Silica with Cobalt Oxide (SiO2 + CoO)) — mineraloid

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Opalite (Synthetic Glass (Amorphized Silicon Dioxide)) — mineraloid

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Common Opal (Green Opal / Pistachio Opal) (Hydrated silica (SiO2·nH2O)) — mineraloid

Common Opal (Green Opal / Pistachio Opal)

Hydrated silica (SiO2·nH2O)