Rock Identifier

Category

Mineraloid (Anthropogenic)

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

Learn about Mineraloid (Anthropogenic) in the encyclopedia

Shungite

White Beryl

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)

Ferruginous Conglomerate (or Iron-Rich Concrete/Slag) (Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)) — sedimentary

Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)

Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)

Tumbled mahogany obsidian (Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions) — igneous

Tumbled mahogany obsidian

Volcanic glass; primarily SiO₂ with iron-oxide-rich brown inclusions

Opalite (Synthetic Glass (Silica-based)) — gemstone

Opalite

Synthetic Glass (Silica-based)

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

Black Obsidian

Amorphous volcanic glass (SiO2)

Obsidian (specifically Mahogany Obsidian) (Volcanic glass (high silica content, SiO2)) — igneous

Obsidian (specifically Mahogany Obsidian)

Volcanic glass (high silica content, SiO2)

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

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

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

Obsidian

Obsidian (Volcanic Glass; SiO2 content > 70%)

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

Mahogany Obsidian

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))

Pearl (Biogenic Mineraloid) (Calcium carbonate (CaCO3) primarily as Aragonite) — mineral

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

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

Fire Opal (in Matrix)

Hydrated Silica (SiO2·nH2O)

Pearl (Biogenic Mineraloid) (Calcium carbonate (Aragonite) and Conchiolin, CaCO3) — mineral

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Polished mahogany obsidian (likely) (Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides) — igneous

Polished mahogany obsidian (likely)

Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides

Polished black obsidian pyramid/block (Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)) — igneous

Polished black obsidian pyramid/block

Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)

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

Mahogany Obsidian

Volcanic glass (SiO2 with Hematite/Magnetite inclusions)

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

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite inclusions)

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

Gold Sheen Obsidian

Volcanic Glass (SiO2 + impurities)

Snowflake Obsidian (Volcanic Glass with Spherulite Inclusions (primarily SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (primarily SiO2)

Black Obsidian (Obsidian (Volcanic Glass)) — igneous

Black 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)

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)

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

Obsidian

Obsidian (Volcanic Glass, SiO2)

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 (predominantly SiO2 with inclusions of Hematite or Magnetite)) — igneous

Mahogany Obsidian

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

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

Mahogany Obsidian

Volcanic glass (SiO2 with Hematite or Magnetite inclusions)

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

Limonite (Iron Ore)

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

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

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (mostly SiO2)

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

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

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

Black Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

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 (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

Banded Slag Glass (Leland Blue/Frankfort Green style) (Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)) — mineral

Banded Slag Glass (Leland Blue/Frankfort Green style)

Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)

Eroded Brick or Pumice-like Scoria (Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)) — igneous

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Obsidian (Obsidian) — igneous

Obsidian

Obsidian