Rock Identifier

Category

Mineral (Sedimentary Context)

Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.

Learn about Mineral (Sedimentary Context) in the encyclopedia

Coal

Claystone

Shale

Marl

Black Shale

Rose quartz (Quartz (SiO₂), pink variety) — mineral

Rose quartz

Quartz (SiO₂), pink variety

Dark weathered pebble, likely basalt (Basalt (fine-grained mafic volcanic rock; commonly plagioclase, pyroxene, and iron oxides)) — igneous

Dark weathered pebble, likely basalt

Basalt (fine-grained mafic volcanic rock; commonly plagioclase, pyroxene, and iron oxides)

Quartz (Iron-stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Black obsidian arrowhead (Obsidian; volcanic glass, typically rhyolitic in composition (mostly SiO₂)) — igneous

Black obsidian arrowhead

Obsidian; volcanic glass, typically rhyolitic in composition (mostly SiO₂)

Flint or chert projectile point (Microcrystalline quartz (SiO₂), likely chalcedony-rich chert) — sedimentary

Flint or chert projectile point

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Greenstone (Greenschist (metamorphosed mafic igneous rock)) — metamorphic

Greenstone

Greenschist (metamorphosed mafic igneous rock)

Dark flint or chert fragment (Microcrystalline quartz (SiO₂), likely chert/flint) — sedimentary

Dark flint or chert fragment

Microcrystalline quartz (SiO₂), likely chert/flint

Lepidolite (K(Li,Al)3(Al,Si,3O10)(F,OH)2) — mineral

Lepidolite

K(Li,Al)3(Al,Si,3O10)(F,OH)2

Chert (Jasper/Flint variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Possible obsidian (black volcanic glass) (Obsidian; natural silica-rich volcanic glass, composition typically rhyolitic) — igneous

Possible obsidian (black volcanic glass)

Obsidian; natural silica-rich volcanic glass, composition typically rhyolitic

Chert (often called Flint in this context) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint in this context)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Smoky variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Smoky variety)

Microcrystalline Quartz (SiO2)

Red Jasper (River Siltstone) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper (River Siltstone)

Silicon Dioxide (SiO2) with iron oxide inclusions

Likely milky quartz fragment (Quartz (silicon dioxide, SiO₂)) — mineral

Likely milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Black Jasper (Silicon dioxide (SiO2)) — sedimentary

Black Jasper

Silicon dioxide (SiO2)

Granite cobble (Granite, a coarse-grained felsic intrusive igneous rock, chiefly quartz, potassium feldspar, plagioclase, and dark biotite or hornblende) — igneous

Granite cobble

Granite, a coarse-grained felsic intrusive igneous rock, chiefly quartz, potassium feldspar, plagioclase, and dark biotite or hornblende

Greenschist (Chlorite Schist (Greenschist Facies)) — metamorphic

Greenschist

Chlorite Schist (Greenschist Facies)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Weathered chert (flint) pebble (Microcrystalline quartz/chalcedony (SiO₂), commonly with iron-oxide staining) — sedimentary

Weathered chert (flint) pebble

Microcrystalline quartz/chalcedony (SiO₂), commonly with iron-oxide staining

Chromium (Chrome) (Chromium (Cr)) — mineral

Chromium (Chrome)

Chromium (Cr)

Citrine (Citrine (Silicon Dioxide, SiO2)) — mineral

Citrine

Citrine (Silicon Dioxide, SiO2)

Tiny amber-colored crystal fragment (Indeterminate; possibly quartz, feldspar, mica, or a sulfide mineral) — mineral

Tiny amber-colored crystal fragment

Indeterminate; possibly quartz, feldspar, mica, or a sulfide mineral

Iron Slag (Industrial Byproduct) (Anthropogenic Vitrification Product/Ferrous Slag) — Mineral-like Industrial Smelting Waste

Iron Slag (Industrial Byproduct)

Anthropogenic Vitrification Product/Ferrous Slag

Mineral-like Industrial Smelting Waste

Obsidian (likely Apache tear or flaked obsidian) (Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, non-crystalline)) — igneous

Obsidian (likely Apache tear or flaked obsidian)

Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, non-crystalline)

Granite (Granite (Phaneritic igneous rock)) — igneous

Granite

Granite (Phaneritic igneous rock)

Flint or chert flake (Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities) — sedimentary

Flint or chert flake

Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities

Shale creek bed (Shale (fine-grained clastic sedimentary rock)) — Sedimentary

Shale creek bed

Shale (fine-grained clastic sedimentary rock)

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

Amber in Matrix

Succinite (Carbon-based organic polymer)

Organic (Sedimentary context)

Prehnite (Prehnite (Ca2Al(AlSi3O10)(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Yellow Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (Red Jasper) (Silicon Dioxide (SiO₂)) — sedimentary

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Ferruginous Sandstone (Ironstone) (Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))) — sedimentary

Ferruginous Sandstone (Ironstone)

Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))

Unidentifiable Rock Fragment — Uncertain

Unidentifiable Rock Fragment

Bronzite (Enstatite (magnesium iron silicate), (Mg,Fe2+)SiO3) — mineral

Bronzite

Enstatite (magnesium iron silicate), (Mg,Fe2+)SiO3

Obsidian (likely) (Volcanic glass, predominantly silica-rich rhyolitic composition (no fixed mineral formula)) — igneous

Obsidian (likely)

Volcanic glass, predominantly silica-rich rhyolitic composition (no fixed mineral formula)

Quartz-rich rock, likely milky quartz vein material (Predominantly quartz (SiO₂); exact rock type cannot be confirmed from the photograph) — igneous

Quartz-rich rock, likely milky quartz vein material

Predominantly quartz (SiO₂); exact rock type cannot be confirmed from the photograph

Granitoid (Granite/Gneiss) (Granitoid silicate rock, primarily quartz and feldspar) — igneous/metamorphic

Granitoid (Granite/Gneiss)

Granitoid silicate rock, primarily quartz and feldspar

igneous/metamorphic

Glass (Amorphous Silicon Dioxide (SiO2)) — mineraloid

Glass

Amorphous Silicon Dioxide (SiO2)

Polished turquoise sphere with purple matrix/inclusion (Turquoise, hydrated copper–aluminum phosphate; approximate formula CuAl₆(PO₄)₄(OH)₈·4H₂O) — mineral

Polished turquoise sphere with purple matrix/inclusion

Turquoise, hydrated copper–aluminum phosphate; approximate formula CuAl₆(PO₄)₄(OH)₈·4H₂O

Gossan (Iron Hat) with Quartz and Chlorite (Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite) — Mineral/Metamorphic Substrate

Gossan (Iron Hat) with Quartz and Chlorite

Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite

Mineral/Metamorphic Substrate

Green Chalcedony (Batu Akik) (Silicon Dioxide (SiO2)) — gemstone

Green Chalcedony (Batu Akik)

Silicon Dioxide (SiO2)

Granite pebble (Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica) — igneous

Granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica