Rock Identifier

Category

Organic (Mineraloid)

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

Learn about Organic (Mineraloid) in the encyclopedia

Shungite

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Jet

Oil Shale

Peat

Pearl

Lizard Skin Jasper

Opalized Wood

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

Black Obsidian

Volcanic Glass (predominantly SiO2)

Amber (Amber (Fossilized Tree Resin)) — Mineral

Amber

Amber (Fossilized Tree Resin)

Black Obsidian (Volcanic Glass (Amorphous SiO2 with trace impurities)) — igneous

Black Obsidian

Volcanic Glass (Amorphous SiO2 with trace impurities)

Obsidian (Volcanic Glass (Amorphous silicon dioxide with impurities)) — igneous

Obsidian

Volcanic Glass (Amorphous silicon dioxide with impurities)

Black Obsidian (Volcanic glass) — igneous

Black Obsidian

Volcanic glass

Obsidian (Volcanic Glass) — igneous

Obsidian

Volcanic Glass

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

Obsidian

Volcanic Glass (SiO2 + impurities)

Fulgurite (Fulgurite (Lechatelierite)) — metamorphic

Fulgurite

Fulgurite (Lechatelierite)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Amber (Succinite (Resinite)) — Organic Crystal (Mineraloid)

Amber

Succinite (Resinite)

Organic Crystal (Mineraloid)

Tumbled black stone, likely black obsidian (Obsidian — volcanic glass, primarily SiO₂) — igneous

Tumbled black stone, likely black obsidian

Obsidian — volcanic glass, primarily SiO₂

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

Gold Sheen Obsidian

Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

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))

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

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

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

White Opal

Hydrated Silica (SiO2·nH2O)

Obsidian (Volcanic Glass (Amorphous SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous SiO2)

Obsidian (Volcanic Glass (SiO2 rich)) — igneous

Obsidian

Volcanic Glass (SiO2 rich)

Polished mahogany obsidian (probable) (Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite) — igneous

Polished mahogany obsidian (probable)

Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Fulgurite (Fulgurite (Lechatelierite-rich fused silica)) — mineraloid / sedimentary (secondary formation)

Fulgurite

Fulgurite (Lechatelierite-rich fused silica)

mineraloid / sedimentary (secondary formation)

Limonite (Iron Ore) (Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)) — Mineral

Limonite (Iron Ore)

Limonite (Hydrated Iron Oxide, 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)

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

Obsidian

Volcanic Glass (70% or more SiO2)

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

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Obsidian (Obsidian (Amorphous volcanic glass, predominantly SiO2)) — igneous

Obsidian

Obsidian (Amorphous volcanic glass, predominantly SiO2)

Obsidian (Volcanic glass) — igneous

Obsidian

Volcanic glass

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

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

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

Limonite (Iron Ore)

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

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

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

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

Limonite/Ironstone

Limonite (FeO(OH)·nH2O)

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

Green Opal

Hydrated Silica (SiO2·nH2O)

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

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurity)

Limonite (Iron Ore) (Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)

Likely obsidian (possibly tektite or slag glass) (Volcanic glass; primarily SiO₂, noncrystalline) — igneous

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

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

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Jet (Lignite (Anthracite-grade compact coal)) — sedimentary

Jet

Lignite (Anthracite-grade compact coal)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Common opal in iron-stained host rock (Opal (hydrated amorphous silica, SiO₂·nH₂O), likely common opal) — mineral

Common opal in iron-stained host rock

Opal (hydrated amorphous silica, SiO₂·nH₂O), likely common opal

Obsidian (black volcanic glass), possibly slag or basalt (Obsidian; chiefly amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition) — igneous

Obsidian (black volcanic glass), possibly slag or basalt

Obsidian; chiefly amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

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

Opal

Hydrated Silica (SiO2·nH2O)