Rock Identifier

Category

Organic Crystal (Mineraloid)

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

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

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

Limonite/Goethite Concretion

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

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

Limonite (Ironstone)

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

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

Common Opal in Host Rock

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

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

Green Opal

Hydrated Silica (SiO2·nH2O)

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)

Fulgurite (Luechatelierite (SiO2 glass)) — mineraloid

Fulgurite

Luechatelierite (SiO2 glass)

Amber (Succinite) — Mineraloid

Amber

Succinite

Burmese Amber (Burmite) (Burmite (C10H16O)) — mineraloid

Burmese Amber (Burmite)

Burmite (C10H16O)

Obsidian (Volcanic Glass (70-75% SiO2)) — igneous

Obsidian

Volcanic Glass (70-75% SiO2)

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

Limonite (Iron Ore)

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

Limonite (Hydrated Iron Oxide / Bog Iron) (FeO(OH)·nH2O) — Mineral (Sedimentary context)

Limonite (Hydrated Iron Oxide / Bog Iron)

FeO(OH)·nH2O

Mineral (Sedimentary context)

Cullet Glass (Slag Glass) (Amorphous Silicon Dioxide (Industrial byproduct)) — mineraloid

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial byproduct)

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

Green Opal or Yellow Opal

Hydrated Silica (SiO2·nH2O)

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

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Tektite (Indochinite) (Tektite (SiO2 + Al2O3)) — mineraloid

Tektite (Indochinite)

Tektite (SiO2 + Al2O3)

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

Opal

Hydrated silica (SiO2·nH2O)

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

Black Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Common Green Opal (Amorphous Hydrous Silica (SiO2·nH2O)) — mineraloid

Common Green Opal

Amorphous Hydrous Silica (SiO2·nH2O)

Tektite (Indochinite) (Tektite (High-silica natural glass)) — mineraloid

Tektite (Indochinite)

Tektite (High-silica natural glass)

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

Precious Opal

Hydrated silica (SiO2·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Amber (Succinite (approximate formula C10H16O)) — mineraloid

Amber

Succinite (approximate formula C10H16O)

Amber (specifically Burmese Amber or Burmite) (Succiniferous fossil resin (C10H16O)) — mineraloid

Amber (specifically Burmese Amber or Burmite)

Succiniferous fossil resin (C10H16O)

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

Limonite (Yellow Ochre)

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

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

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Black Opal (Hydrated Silica (SiO2·nH2O)) — Mineraloid

Black Opal

Hydrated Silica (SiO2·nH2O)

Cullet Glass (Slag) (Amorphous Silicon Dioxide (Man-made)) — Mineraloid

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

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

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

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)

Glass (Amorphous Silicon Dioxide (SiO2)) — mineraloid

Glass

Amorphous Silicon Dioxide (SiO2)

Black Obsidian (Volcanic Glass (SiO2)) — igneous

Black Obsidian

Volcanic Glass (SiO2)

Black Opal (Kalimaya) (Hydrated Silica (SiO2·nH2O)) — mineraloid

Black Opal (Kalimaya)

Hydrated Silica (SiO2·nH2O)

Opalite (Synthetic glass (SiO2 + metal additions)) — mineraloid

Opalite

Synthetic glass (SiO2 + metal additions)

Black Obsidian (Volcanic glass (Amorphous silicates)) — igneous

Black Obsidian

Volcanic glass (Amorphous silicates)

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)

Boulder Opal (Hydrated Silica (SiO2·nH2O)) — mineraloid

Boulder Opal

Hydrated Silica (SiO2·nH2O)

Tektite (Indochinite) (Tektite (High-silica impact glass)) — mineraloid

Tektite (Indochinite)

Tektite (High-silica impact glass)

Cullet Glass (Man-made Glass Slag) (Amorphous Silica (SiO2) with chemical additives) — Mineraloid

Cullet Glass (Man-made Glass Slag)

Amorphous Silica (SiO2) with chemical additives

Cobalt Glass Slug (Cullet) (Man-made Silicate Glass with Cobalt Oxide (CoO)) — mineraloid

Cobalt Glass Slug (Cullet)

Man-made Silicate Glass with Cobalt Oxide (CoO)