Rock Identifier

Category

Mineraloid (Anthropogenic)

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

Learn about Mineraloid (Anthropogenic) in the encyclopedia

Shungite

White Beryl

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)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Pearl (Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3) — mineral

Pearl

Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3

Greenstone Celt (Polished Stone Axe) (Metamorphosed mafic rock (often Basalt or Diabase)) — metamorphic

Greenstone Celt (Polished Stone Axe)

Metamorphosed mafic rock (often Basalt or Diabase)

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)

Amber in Matrix (Succinite (Carbon-based organic polymer)) — Organic (Sedimentary context)

Amber in Matrix

Succinite (Carbon-based organic polymer)

Organic (Sedimentary context)

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)

Possible basaltic volcanic rock or iron-rich meteorite (Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually) — igneous

Possible basaltic volcanic rock or iron-rich meteorite

Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually

Shungite (Carbon-rich mineraloid (Amorphous carbon)) — mineral

Shungite

Carbon-rich mineraloid (Amorphous carbon)

Shungite (Shungite (carbon-rich Precambrian mineraloid)) — mineral

Shungite

Shungite (carbon-rich Precambrian mineraloid)

Pearl (Biogenic Mineraloid) (Calcium carbonate (Aragonite) and Conchiolin, CaCO3) — mineral

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

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

Green Opal

Hydrated Silica (SiO2·nH2O)

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)

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

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

Blue slag glass / industrial smelter slag (Man-made iron-rich silicate slag; composition variable, commonly Fe–Ca–Mg–Al silicates with glassy phases) — mineral

Blue slag glass / industrial smelter slag

Man-made iron-rich silicate slag; composition variable, commonly Fe–Ca–Mg–Al silicates with glassy phases

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)

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)

Limonite (Ironstone) (Limonite (mixture of hydrated iron(III) oxide-hydroxides)) — mineral

Limonite (Ironstone)

Limonite (mixture of hydrated iron(III) oxide-hydroxides)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Iron-rich slag or weathered ironstone fragments (Probably hematite–goethite material; possibly industrial iron slag (Fe₂O₃/FeO(OH))) — mineral

Iron-rich slag or weathered ironstone fragments

Probably hematite–goethite material; possibly industrial iron slag (Fe₂O₃/FeO(OH))

Concrete-like aggregate surface with embedded rock fragments (Anthropogenic concrete or exposed aggregate; not a natural rock specimen) — sedimentary

Concrete-like aggregate surface with embedded rock fragments

Anthropogenic concrete or exposed aggregate; not a natural rock specimen

Banded Slag Glass (Leland Blue/Frankfort Green style) (Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)) — mineral

Banded Slag Glass (Leland Blue/Frankfort Green style)

Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)

Eroded Brick or Pumice-like Scoria (Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)) — igneous

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Opal (in Jewelry Setting) (Hydrated Silicon Dioxide (SiO2·nH2O)) — gemstone

Opal (in Jewelry Setting)

Hydrated Silicon Dioxide (SiO2·nH2O)

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

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

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