Rock Identifier

Category

Biogenic Material

Browse biogenic material specimens identified by the Rock Identifier community.

Learn about Biogenic Material in the encyclopedia

Peat

Diatomite

Dunite

Limonite

Diamond

Peacock Opal

Metarhyolite

Rhodochrosite

Shell Opal

Madagascar Opal

Lavender Obsidian

Electric Blue Obsidian

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Flower Jasper (Agatized Fossil Coral / Chalcedony (SiO2)) — sedimentary

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

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

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (Jasper variation) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (often called Flint when in chalk or limestone) (Silicon Dioxide (SiO₂)) — sedimentary

Chert (often called Flint when in chalk or limestone)

Silicon Dioxide (SiO₂)

Cubic Zirconia (Zirconium Dioxide (ZrO2)) — mineral

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Chert (variably Oolitic or Fossiliferous) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variably Oolitic or Fossiliferous)

Sedimentary Cryptocrystalline Quartz (SiO2)

Tiger Shark Fossil Tooth (Galeocerdo cuvier (fossilized)) — sedimentary

Tiger Shark Fossil Tooth

Galeocerdo cuvier (fossilized)

Chert (Nodule) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2)

Coquina or Fossiliferous Limestone (Fossiliferous Calcarenite (CaCO3)) — sedimentary

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Polished brecciated jasper (Jasper, opaque microcrystalline quartz (SiO₂), likely brecciated jasper with iron-oxide and dark silicate inclusions) — mineral

Polished brecciated jasper

Jasper, opaque microcrystalline quartz (SiO₂), likely brecciated jasper with iron-oxide and dark silicate inclusions

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Red jasper (likely hematite-rich jasper) (Microcrystalline quartz (SiO₂) with iron oxides, chiefly hematite (Fe₂O₃)) — mineral

Red jasper (likely hematite-rich jasper)

Microcrystalline quartz (SiO₂) with iron oxides, chiefly hematite (Fe₂O₃)

Green cabochon gemstone pendant (Indeterminate; likely dyed green turquoise, chrysoprase, or opaque beryl set with blue/clear accent stones) — gemstone

Green cabochon gemstone pendant

Indeterminate; likely dyed green turquoise, chrysoprase, or opaque beryl set with blue/clear accent stones

Polished opal-like chalcedony (Cryptocrystalline silica, SiO₂; likely common opal or pale chalcedony, with identification limited by the photograph) — gemstone

Polished opal-like chalcedony

Cryptocrystalline silica, SiO₂; likely common opal or pale chalcedony, with identification limited by the photograph

Amethyst quartz cluster (Quartz, SiO₂; purple coloration from iron impurities and irradiation) — mineral

Amethyst quartz cluster

Quartz, SiO₂; purple coloration from iron impurities and irradiation

Sandstone (with vugs) (Arenite / Sedimentary Sandstone) — sedimentary

Sandstone (with vugs)

Arenite / Sedimentary Sandstone

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

Red Jasper

Jasper (Silicon Dioxide, SiO2)

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

Chert (Flint Nodules)

Silicon Dioxide (SiO2)

Rounded gray metamorphic cobble, likely quartzite or gneiss (Quartz-rich metamorphic rock; possibly quartzite (mostly SiO₂) or banded gneiss) — metamorphic

Rounded gray metamorphic cobble, likely quartzite or gneiss

Quartz-rich metamorphic rock; possibly quartzite (mostly SiO₂) or banded gneiss

Tumbled brown quartz/chert pebble (Microcrystalline quartz (SiO₂), possibly chert or jasper) — mineral

Tumbled brown quartz/chert pebble

Microcrystalline quartz (SiO₂), possibly chert or jasper

Polished blue agate/geode slice (Chalcedony (microcrystalline quartz, SiO₂), likely dyed blue) — mineral

Polished blue agate/geode slice

Chalcedony (microcrystalline quartz, SiO₂), likely dyed blue

Quartz with Sericite and Cinnabar (Silicon Dioxide (SiO2) with muscovite/sericite and mercury sulfide (HgS)) — mineral

Quartz with Sericite and Cinnabar

Silicon Dioxide (SiO2) with muscovite/sericite and mercury sulfide (HgS)

Citrine (Silicon Dioxide (SiO2)) — mineral

Citrine

Silicon Dioxide (SiO2)

Dyed Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Quartz-rich pebble, possibly chert or silicified limestone (Microcrystalline quartz (SiO₂), possibly chalcedony; exact identification is uncertain from the photograph) — sedimentary

Quartz-rich pebble, possibly chert or silicified limestone

Microcrystalline quartz (SiO₂), possibly chalcedony; exact identification is uncertain from the photograph

Tumbled carnelian (Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)) — gemstone

Tumbled carnelian

Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)

Weathered quartz-rich rock, possibly milky quartz or quartz-bearing granite (Quartz (SiO₂), potentially with feldspar and iron-oxide staining) — mineral

Weathered quartz-rich rock, possibly milky quartz or quartz-bearing granite

Quartz (SiO₂), potentially with feldspar and iron-oxide staining

Weathered granite pebble (Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole) — igneous

Weathered granite pebble

Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole

Slag Glass (SiO2 (Silicon Dioxide) with impurities) — man-made glass

Slag Glass

SiO2 (Silicon Dioxide) with impurities

Diamond (Carbon (C)) — gemstone

Diamond

Carbon (C)

Quartz Veined Basalt (Mafic Igneous Rock with Quartz (SiO2) intrusion) — igneous

Quartz Veined Basalt

Mafic Igneous Rock with Quartz (SiO2) intrusion

Basalt (River Pebble) (Aphanitic Mafic Igneous Rock) — igneous

Basalt (River Pebble)

Aphanitic Mafic Igneous Rock

Yellow Diamond (Faceted) (Diamond (pure carbon) with nitrogen impurities, C) — mineral

Yellow Diamond (Faceted)

Diamond (pure carbon) with nitrogen impurities, C

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Diamond (Faceted) (Carbon (C)) — mineral

Diamond (Faceted)

Carbon (C)

Rough Citrine Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Rough Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Mystic Topaz (Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)) — mineral

Mystic Topaz

Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)

Chert (with potential fossil inclusion) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with potential fossil inclusion)

Microcrystalline Quartz (SiO2)

Tumbled gray-green metamorphic rock, likely serpentinite or chlorite schist (Serpentinite/chlorite-rich ultramafic metamorphic rock; commonly dominated by antigorite, lizardite, or chlorite with minor magnetite and talc) — metamorphic

Tumbled gray-green metamorphic rock, likely serpentinite or chlorite schist

Serpentinite/chlorite-rich ultramafic metamorphic rock; commonly dominated by antigorite, lizardite, or chlorite with minor magnetite and talc