Rock Identifier

Category

Organic Crystal (Mineraloid)

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

Pearl (Imitation or Cultured) (Calcium Carbonate (Aragonite/Calcite) - CaCO3) — Mineraloid (Organic)

Pearl (Imitation or Cultured)

Calcium Carbonate (Aragonite/Calcite) - CaCO3

Mineraloid (Organic)

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

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

Opal

Hydrated silica (SiO2 "NH2O)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

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

Opal

Hydrated amorphous silica (SiO2·nH2O)

Limonite/Ironstone (Limonite (FeO(OH)·nH2O)) — mineral

Limonite/Ironstone

Limonite (FeO(OH)·nH2O)

Amber (Succinite (specifically for Baltic amber); Approximate formula: C10H16O) — Organic Gemstone (Mineraloid)

Amber

Succinite (specifically for Baltic amber); Approximate formula: C10H16O

Organic Gemstone (Mineraloid)

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

Black obsidian (likely)

Volcanic glass; primarily silica-rich, noncrystalline SiO₂ composition

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

Black Obsidian

Obsidian (Amorphous Silicon Dioxide)

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

Snowflake Obsidian

Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)

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

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

Polished amber (Amber (fossilized plant resin), commonly succinite; organic mineraloid rather than a true mineral) — gemstone

Polished amber

Amber (fossilized plant resin), commonly succinite; organic mineraloid rather than a true mineral

Snowflake Obsidian (Volcanic glass containing Spherulitic Cristobalite (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulitic Cristobalite (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

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)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Limonite or Ironstone Nodule (FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)) — sedimentary

Limonite or Ironstone Nodule

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

Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — Mineral

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

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

White Precious Opal

Hydrated Silica (SiO2·nH2O)

Obsidian (Volcanic glass (SiO2 + impurities)) — igneous

Obsidian

Volcanic glass (SiO2 + impurities)

Polished mahogany obsidian (Volcanic glass; predominantly silica-rich rhyolitic composition (SiO₂)) — igneous

Polished mahogany obsidian

Volcanic glass; predominantly silica-rich rhyolitic composition (SiO₂)

Gold Sheen Obsidian (Obsidian (volcanic glass with SiO2 + gas inclusions)) — igneous

Gold Sheen Obsidian

Obsidian (volcanic glass with SiO2 + gas inclusions)

Black Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Black Obsidian

Volcanic Glass (predominantly SiO2)

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

Snowflake Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)

Orange cabochon gemstone, likely amber or amber-like resin (Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing) — gemstone

Orange cabochon gemstone, likely amber or amber-like resin

Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing

Polished black stone, likely shungite (Shungite; carbon-rich mineraloid composed mainly of amorphous carbon, with silica and other minerals) — mineral

Polished black stone, likely shungite

Shungite; carbon-rich mineraloid composed mainly of amorphous carbon, with silica and other minerals

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

Common Opal (Green Opal / Pistachio Opal)

Hydrated silica (SiO2·nH2O)

Obsidian (likely black obsidian) (Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)) — igneous

Obsidian (likely black obsidian)

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Obsidian (likely black obsidian) (Volcanic glass; primarily SiO₂-rich rhyolitic composition) — igneous

Obsidian (likely black obsidian)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

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

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Obsidian (black volcanic glass) (Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)) — igneous

Obsidian (black volcanic glass)

Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)

Tumbled black obsidian (likely) (Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)) — igneous

Tumbled black obsidian (likely)

Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)

Obsidian (likely black volcanic glass) (Obsidian; silica-rich, noncrystalline volcanic glass, typically rhyolitic (approximately 70–75% SiO₂)) — igneous

Obsidian (likely black volcanic glass)

Obsidian; silica-rich, noncrystalline volcanic glass, typically rhyolitic (approximately 70–75% SiO₂)

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

Obsidian

Obsidian (Volcanic Glass), primarily SiO2

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

Precious Opal

SiO2·nH2O (Hydrated Silicon Dioxide)

Fulgurite (Fulgurite (Lechatelierite)) — metamorphic

Fulgurite

Fulgurite (Lechatelierite)

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

Limonite (Iron Ore)

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

Snowflake Obsidian (Volcanic Glass with Spherulite Inclusions (70–75% SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (70–75% SiO2)

Polished amber (Amber (fossilized plant resin), commonly succinite; organic mineraloid rather than a true mineral) — gemstone

Polished amber

Amber (fossilized plant resin), commonly succinite; organic mineraloid rather than a true mineral

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

Limonite (with Pyrite)

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