Rock Identifier

Category

Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)

Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.

Diorite (Gneissic) (Diorite) — igneous

Diorite (Gneissic)

Diorite

Chert (Yellow/Tan variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate) (N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)) — Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)

N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)

Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)

Ruby (Corundum (Al2O3:Cr)) — mineral

Ruby

Corundum (Al2O3:Cr)

Dyed Quartz Geode (Silicon Dioxide (SiO2) with artificial pigment) — mineral

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

US Penny (Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy) — Man-made object (metal alloy)

US Penny

Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy

Man-made object (metal alloy)

Coral Rock (Coquina) (Biogenic Limestone (Calcium Carbonate - CaCO3)) — sedimentary

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Limonite Concretion (Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O) — sedimentary

Limonite Concretion

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

Fuchsite (Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)) — mineral

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Rhyolite (Rhyolite (Extrusive Felsic Igneous Rock)) — igneous

Rhyolite

Rhyolite (Extrusive Felsic Igneous Rock)

Apache Tear (Hydrated Obsidian (Volcanic Glass)) — igneous

Apache Tear

Hydrated Obsidian (Volcanic Glass)

Mahogany Obsidian Arrowhead (Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)) — igneous

Mahogany Obsidian Arrowhead

Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)

Tektite (Indochinite) (Tektite (High-silica natural glass)) — igneous

Tektite (Indochinite)

Tektite (High-silica natural glass)

Ironstone Concretion (Siderite or Limonite Concretion) — sedimentary

Ironstone Concretion

Siderite or Limonite Concretion

Chert (Common Variety, Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Common Variety, Jasper)

Microcrystalline Quartz (SiO2)

Chrysoprase (Chalcedony (Silicon Dioxide, SiO2), flavored by Nickel) — mineral

Chrysoprase

Chalcedony (Silicon Dioxide, SiO2), flavored by Nickel

Pyrite in Shale (Iron Sulfide (FeS2)) — mineral

Pyrite in Shale

Iron Sulfide (FeS2)

Sodalite-rich Syenite (Sunset Sodalite) (Sodalite-Syenite (Na8[Al6Si6O24]Cl2 with KAlSi3O8)) — igneous

Sodalite-rich Syenite (Sunset Sodalite)

Sodalite-Syenite (Na8[Al6Si6O24]Cl2 with KAlSi3O8)

Chrysocolla in Quartz (Gem Silica) (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)) — mineral

Chrysocolla in Quartz (Gem Silica)

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)

Yellow Aventurine (Quartz containing Muscovite or Mica inclusions (SiO2)) — mineral

Yellow Aventurine

Quartz containing Muscovite or Mica inclusions (SiO2)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen) (Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.) — Metamorphic, Mineral (within a rock type)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Metamorphic, Mineral (within a rock type)

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

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Amethyst (Amethyst (SiO2 - Silicon Dioxide with Iron impurities)) — mineral

Amethyst

Amethyst (SiO2 - Silicon Dioxide with Iron impurities)

Hematite (Iron(III) oxide (Fe2O3)) — mineral

Hematite

Iron(III) oxide (Fe2O3)

Ironstone Concretion (Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)) — sedimentary

Ironstone Concretion

Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)

Sandstone with Iron Concretion (Arenite with Limonite/Goethite Concretion) — sedimentary

Sandstone with Iron Concretion

Arenite with Limonite/Goethite Concretion

Man-made Blank Ammunition (Brass) (CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)) — Anticrystalline / Synthetic Alloy

Man-made Blank Ammunition (Brass)

CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)

Anticrystalline / Synthetic Alloy

Black Spinel (Magnesium Aluminum Oxide (MgAl2O4)) — mineral

Black Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Yellow Aventurine (Quartzite with inclusions (SiO2)) — metamorphic

Yellow Aventurine

Quartzite with inclusions (SiO2)

Beryl (Emerald or Aquamarine in Matrix) (Beryllium Aluminum Silicate (Be3Al2Si6O18)) — mineral

Beryl (Emerald or Aquamarine in Matrix)

Beryllium Aluminum Silicate (Be3Al2Si6O18)

Ironstone Concretion (Limonite/Goethite) (Iron oxide concretion (contains FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Limonite/Goethite)

Iron oxide concretion (contains FeO(OH)·nH2O)

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right) (Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)) — mineral

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right)

Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)

Scoria (Vesicular Basalt) (Scoria (Extrusive Igneous Rock)) — igneous

Scoria (Vesicular Basalt)

Scoria (Extrusive Igneous Rock)

Sandstone (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Quartz Arenite) (Sandstone (dominated by SiO2 quartz grains)) — sedimentary

Sandstone (Quartz Arenite)

Sandstone (dominated by SiO2 quartz grains)

Diamond (Diamond (pure Carbon, C)) — mineral

Diamond

Diamond (pure Carbon, C)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Apache Tear (Obsidian (Hydrated Volcanic Glass) - SiO2 (with impurities)) — igneous

Apache Tear

Obsidian (Hydrated Volcanic Glass) - SiO2 (with impurities)

Opalite (Synthetic Opalised Glass) — Mineral (Synthetic / Man-made)

Opalite

Synthetic Opalised Glass

Mineral (Synthetic / Man-made)

Libyan Desert Glass (Impact-melt silica glass (SiO2 + traces of Al, Fe, Ti)) — mineral (Tektite/Impactite)

Libyan Desert Glass

Impact-melt silica glass (SiO2 + traces of Al, Fe, Ti)

mineral (Tektite/Impactite)

Sandstone Concretion (Sandstone (Sedimentary Rock) with silica or calcite cement) — sedimentary

Sandstone Concretion

Sandstone (Sedimentary Rock) with silica or calcite cement

Chert (Chalcedony/Agate variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)