Rock Identifier

Category

Organic Crystal (Mineraloid)

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

Black Obsidian (Volcanic Glass (SiO2 + impurities)) — Igneous

Black Obsidian

Volcanic Glass (SiO2 + impurities)

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

Obsidian (specifically Mahogany Obsidian)

Volcanic glass (high silica content, SiO2)

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

Obsidian

Obsidian (Volcanic Glass, SiO2)

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

Mahogany Obsidian

Volcanic glass (SiO2 with Hematite or Magnetite inclusions)

Black obsidian (Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)) — igneous

Black obsidian

Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)

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

Black Obsidian

Amorphous volcanic glass (SiO2)

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

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

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

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)

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)

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

Snowflake Obsidian

Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions

Black Obsidian (Obsidian (Volcanic Glass)) — igneous

Black Obsidian

Obsidian (Volcanic Glass)

Obsidian (likely black volcanic glass) (Obsidian; predominantly silica-rich rhyolitic volcanic glass (approximately 70– on 80% SiO₂)) — igneous

Obsidian (likely black volcanic glass)

Obsidian; predominantly silica-rich rhyolitic volcanic glass (approximately 70– on 80% SiO₂)

Polished black obsidian (Volcanic glass, predominantly rhyolitic silica (SiO₂)) — igneous

Polished black obsidian

Volcanic glass, predominantly rhyolitic silica (SiO₂)

Likely obsidian fragment (Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich)) — igneous

Likely obsidian fragment

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

Obsidian (likely Apache tear or flaked obsidian) (Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, non-crystalline)) — igneous

Obsidian (likely Apache tear or flaked obsidian)

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

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

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite inclusions)

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)

Amber (Fossilized Tree Resin (Succinite)) — mineraloid

Amber

Fossilized Tree Resin (Succinite)

Limonite (Ironstone) (Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))) — mineral

Limonite (Ironstone)

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

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

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (mostly SiO2)

Obsidian (Obsidian) — igneous

Obsidian

Obsidian

Tumbled amber-like gemstone (Likely amber (fossilized resin; organic mineraloid), possibly citrine or yellow-brown glass imitation) — gemstone

Tumbled amber-like gemstone

Likely amber (fossilized resin; organic mineraloid), possibly citrine or yellow-brown glass imitation

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

White Opal

Hydrated Silica (SiO2·nH2O)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

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

Opal (Precious Opal)

Hydrated Silica (SiO2·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Gold Sheen Obsidian (Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)) — igneous

Gold Sheen Obsidian

Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

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

Obsidian (Gold Sheen)

Obsidian (SiO2 + impurities)

Probable amber fragment (Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)) — gemstone

Probable amber fragment

Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)

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

Obsidian (likely snowflake-free black variety)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Polished black obsidian (Volcanic glass; primarily silica-rich rhyolitic glass (approximately 70–80% SiO₂)) — igneous

Polished black obsidian

Volcanic glass; primarily silica-rich rhyolitic glass (approximately 70–80% SiO₂)

Polished black obsidian (Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–80% SiO₂)) — igneous

Polished black obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–80% SiO₂)

Black obsidian (Volcanic glass; predominantly rhyolitic silica-rich melt (approximately 70–80% SiO₂), lacking crystalline structure) — igneous

Black obsidian

Volcanic glass; predominantly rhyolitic silica-rich melt (approximately 70–80% SiO₂), lacking crystalline structure

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

Black Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

Obsidian (Volcanic Glass (SiO2 rich)) — Igneous

Obsidian

Volcanic Glass (SiO2 rich)

Amber (Succinite (fossilized tree resin)) — mineraloid / sedimentary organic material

Amber

Succinite (fossilized tree resin)

mineraloid / sedimentary organic material

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

Mahogany Obsidian

Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)

Polished mahogany obsidian (Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)) — igneous

Polished mahogany obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)