Rock Identifier

Category

Organic Crystal (Mineraloid)

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

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

Limonite (Iron Ore)

Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O

Obsidian (Obsidian (principally SiO2 with MgO and Fe3O4)) — igneous

Obsidian

Obsidian (principally SiO2 with MgO and Fe3O4)

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)

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)

Conch Pearl (Calcareous concretion (CaCO3)) — mineraloid

Conch Pearl

Calcareous concretion (CaCO3)

Amber (Succinite (C10H16O)) — mineraloid

Amber

Succinite (C10H16O)

Fulgurite (Liesegang (Fulgurite)) — Mineraloid

Fulgurite

Liesegang (Fulgurite)

White Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — Mineraloid

White Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Sea Glass (Frosted Quartz/Glass) (Amorphous Silicon Dioxide (SiO2)) — Mineraloid

Sea Glass (Frosted Quartz/Glass)

Amorphous Silicon Dioxide (SiO2)

Black Opal (Hydrated silica (SiO2·nH2O)) — mineraloid

Black Opal

Hydrated silica (SiO2·nH2O)

Sea Glass (often mistaken for Gemstones) (Amorphous Silica (SiO2) with trace additives) — mineraloid

Sea Glass (often mistaken for Gemstones)

Amorphous Silica (SiO2) with trace additives

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

Obsidian

Volcanic glass (high silica volcanic rock)

White Opal (Common) (Hydrated Silica (SiO2·nH2O)) — mineral

White Opal (Common)

Hydrated Silica (SiO2·nH2O)

Cobalt Blue Slag Glass (Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives) — mineraloid

Cobalt Blue Slag Glass

Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives

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

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Opal (Hydrated silica (SiO2·nH2O)) — mineraloid

Opal

Hydrated silica (SiO2·nH2O)

Amber (Succinite (approximate formula C10H16O)) — mineraloid

Amber

Succinite (approximate formula C10H16O)

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

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

Fire Opal (in matrix) (Hydrated Silica (SiO2·nH2O)) — Mineraloid

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

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

Obsidian

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

Slag (Industrial Glass) (Anthropogenic Amorphous Vitreous Silicate) — mineraloid

Slag (Industrial Glass)

Anthropogenic Amorphous Vitreous Silicate

Ethiopian Opal (Welo Opal) (Hydrated Amorphous Silica (SiO2·nH2O)) — mineraloid

Ethiopian Opal (Welo Opal)

Hydrated Amorphous Silica (SiO2·nH2O)

Obsidian (Amorphous volcanic glass (SiO2)) — igneous

Obsidian

Amorphous volcanic glass (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Obsidian (Obsidian (Volcanic Glass)) — Igneous

Obsidian

Obsidian (Volcanic Glass)

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)

Amber (and Citrine Quartz) (Succinite (Amber) and Silicon Dioxide (SiO2)) — Organic Mineraloid and Mineral

Amber (and Citrine Quartz)

Succinite (Amber) and Silicon Dioxide (SiO2)

Organic Mineraloid and Mineral

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

Baltic Amber (Butterscotch variety)

Succinite

Organic Gemstone/Mineraloid

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))

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

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)

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)

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 with Hematite/Magnetite inclusions) — igneous

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

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

Mahogany Obsidian

Volcanic Glass (Silicate: SiO2 + Fe2O3)

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

Limonite (Iron Ore)

Hydrous ferric oxides (FeO(OH)·nH2O)

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

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)

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

Obsidian

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

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

Obsidian

Obsidian (volcanic glass; primarily SiO2)

Amber (Resinite / Fossilized Tree Resin) — mineral

Amber

Resinite / Fossilized Tree Resin