Rock Identifier

Category

Mineraloid (Human Made Geological Specimen)

Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Diamond (Cut Gemstone) (Natural Carbon (C)) — gemstone

Diamond (Cut Gemstone)

Natural Carbon (C)

Chert (Nodule/Pebble) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Nodule/Pebble)

Chert (Silicon Dioxide, SiO2)

Chert (Jasper/Flint variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)

Chert with Limestone (Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) Matrix) — sedimentary

Chert with Limestone

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) Matrix

Chert / Flint (Artifact) (Microcrystalline quartz (SiO2)) — sedimentary

Chert / Flint (Artifact)

Microcrystalline quartz (SiO2)

Chert (specifically Zebra Chert/Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Zebra Chert/Flint)

Silicon Dioxide (SiO2)

Obsidian (Obsidian (volcanic glass; primarily SiO2)) — igneous

Obsidian

Obsidian (volcanic glass; primarily SiO2)

Chert (specifically Jasper or Flint variety) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint variety)

Cryptocrystalline Quartz (SiO2)

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

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

Quartz crystal (likely clear quartz) (Quartz, silicon dioxide (SiO₂)) — mineral

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Granite countertop slab (Granite; primarily quartz, feldspar, and mica (commonly biotite), with accessory amphibole/iron oxides) — igneous

Granite countertop slab

Granite; primarily quartz, feldspar, and mica (commonly biotite), with accessory amphibole/iron oxides

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Tumbled brown jasper (likely brecciated or scenic jasper) (Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions) — mineral

Tumbled brown jasper (likely brecciated or scenic jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Possible weathered basalt or slag fragment (Basalt, chiefly plagioclase and pyroxene; identification is uncertain from the image) — igneous

Possible weathered basalt or slag fragment

Basalt, chiefly plagioclase and pyroxene; identification is uncertain from the image

Weathered iron-rich concretion or ironstone nodule (Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)) — sedimentary

Weathered iron-rich concretion or ironstone nodule

Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)

Jasper (Silicon Dioxide (Microcrystalline Quartz, SiO2)) — sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Chert (Chert (microcrystalline quartz)) — sedimentary

Chert

Chert (microcrystalline quartz)

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)

Carved white translucent mineral specimen (Likely calcite (CaCO₃), possibly milky quartz (SiO₂)) — mineral

Carved white translucent mineral specimen

Likely calcite (CaCO₃), possibly milky quartz (SiO₂)

Ceramic or Polished Stone Heart (Anthropogenic Material) (Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)) — Synthetic/Anthropogenic Mineraloid

Ceramic or Polished Stone Heart (Anthropogenic Material)

Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)

Synthetic/Anthropogenic Mineraloid

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

Obsidian (specifically Mahogany Obsidian)

Volcanic glass (high silica content, SiO2)

Black Obsidian (Obsidian (Volcanic Glass)) — igneous

Black Obsidian

Obsidian (Volcanic Glass)

Tumbled agate (likely moss or brecciated agate) (Microcrystalline quartz, mainly chalcedony (SiO₂), with iron-oxide inclusions) — gemstone

Tumbled agate (likely moss or brecciated agate)

Microcrystalline quartz, mainly chalcedony (SiO₂), with iron-oxide inclusions

Synthetic Faux Fur Fursuit (Polyacrylonitrile / Polyester (Synthetic Textile)) — not a rock (synthetic material/costume)

Synthetic Faux Fur Fursuit

Polyacrylonitrile / Polyester (Synthetic Textile)

not a rock (synthetic material/costume)

Land Snail Shell (Gastropoda (Calcium Carbonate, CaCO3)) — fossil

Land Snail Shell

Gastropoda (Calcium Carbonate, CaCO3)

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

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Chert (and Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Flint)

Silicon Dioxide (SiO2)

Limonitic Iron Ore / Goethite (Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)) — sedimentary

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite inclusions)

Diamond (Carbon (C)) — gemstone

Diamond

Carbon (C)

Flint / Chert (Beach-worn Pebble) (Microcrystalline quartz (SiO2)) — sedimentary

Flint / Chert (Beach-worn Pebble)

Microcrystalline quartz (SiO2)

Milky quartz (likely quartz crystal fragment) (Quartz, silicon dioxide (SiO₂)) — mineral

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Serpentine-rich metamorphic rock (probable serpentinite) (Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and chromite) — metamorphic

Serpentine-rich metamorphic rock (probable serpentinite)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and chromite

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Brecciated Jasper (Brecciated Jasper (Microcrystalline Quartz / SiO2)) — sedimentary

Brecciated Jasper

Brecciated Jasper (Microcrystalline Quartz / SiO2)

Chert (potentially Jasper/Common Opal mixture) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (potentially Jasper/Common Opal mixture)

Microcrystalline Quartz (SiO2)