Rock Identifier

Category

Organic (Mineraloid)

Browse organic (mineraloid) specimens identified by the Rock Identifier community.

Obsidian (Obsidian (Volcanic Glass; SiO2 content > 70%)) — igneous

Obsidian

Obsidian (Volcanic Glass; SiO2 content > 70%)

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

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Limonite (Iron Stone/Goethite) (Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))) — mineral

Limonite (Iron Stone/Goethite)

Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))

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

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

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

Snowflake Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)

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

Snowflake Obsidian

Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions

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

Mahogany Obsidian

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

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

Obsidian

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

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

Obsidian

Volcanic glass (high silica volcanic rock)

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)

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

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)

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

Obsidian

Obsidian (Volcanic Glass), primarily SiO2

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Limonite (Iron Ore Congcretion) (Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore Congcretion)

Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)

Fire Opal (in Matrix) (Hydrated Silica (SiO2·nH2O)) — mineral

Fire Opal (in Matrix)

Hydrated Silica (SiO2·nH2O)

Black Obsidian (Obsidian (Volcanic Glass, ~70% SiO2)) — igneous

Black Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

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

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

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

Snowflake Obsidian (Flower Jasper variant)

Vitreous volcanic silicate with cristobalite inclusions

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

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 (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)

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

Limonite (with Pyrite)

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

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

Limonite (Iron Ore)

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

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

Obsidian

Obsidian (Volcanic Glass, SiO2)

Limonitic Iron Ore / Goethite (Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)) — sedimentary

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

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

Obsidian

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

Mahogany Obsidian (Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)) — igneous

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)

Limonite (Iron Ore) (Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

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

Mahogany Obsidian (Volcanic glass (SiO2 with Hematite or Magnetite inclusions)) — igneous

Mahogany Obsidian

Volcanic glass (SiO2 with Hematite or Magnetite inclusions)

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

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (mostly SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Snowflake Obsidian

Spherulitic Volcanic Glass (SiO2 + impurities)

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)

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

Obsidian (Gold Sheen)

Obsidian (SiO2 + impurities)

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

Mahogany Obsidian

Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)

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

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)

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)