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) — igneous

Obsidian

Volcanic Glass

Obsidian (Volcanic Glass) — igneous

Obsidian

Volcanic Glass

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)

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)

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

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)

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)

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

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)

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)

Amber with Inclusion (Succiniferous fossil resin (C10H16O)) — mineraloid

Amber with Inclusion

Succiniferous fossil resin (C10H16O)

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

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)

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))

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

Precious Opal

SiO2·nH2O (Hydrated Silicon Dioxide)

Black Pearl (Tahitian Pearl) (Aragonite / Calcite (CaCO3) with Conchiolin) — mineral

Black Pearl (Tahitian Pearl)

Aragonite / Calcite (CaCO3) with Conchiolin

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

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

Mahogany Obsidian

Volcanic Glass with Hematite (SiO2 + Fe2O3)

Black Obsidian (Volcanic Glass (SiO2 + impurities like Fe3O4)) — igneous

Black Obsidian

Volcanic Glass (SiO2 + impurities like Fe3O4)

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

Opal

Hydrated silica (SiO2 "NH2O)

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

Snowflake Obsidian

Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)

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

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

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

Snowflake Obsidian

Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions