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

Tumbled blue stone, likely sodalite (Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly blue calcite or dyed material) — mineral

Tumbled blue stone, likely sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly blue calcite or dyed material

Yellow-green jasper or serpentine-rich rock (Likely microcrystalline quartz (SiO₂) with iron-bearing and/or serpentine minerals; exact identification requires testing) — mineral

Yellow-green jasper or serpentine-rich rock

Likely microcrystalline quartz (SiO₂) with iron-bearing and/or serpentine minerals; exact identification requires testing

Petrified Wood (Silicified wood (Quartz/Chalcedony - SiO2)) — mineral

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Chert (often called Flint or Jasper based on color) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper based on color)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Serpentinite (Serpentinite; chiefly serpentine-group minerals (lizardite, chrysotile, antigorite), commonly with magnetite and minor talc) — metamorphic

Serpentinite

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

Tumbled purple agate (likely grape agate or amethystine chalcedony) (Microcrystalline quartz, SiO₂; purple coloration commonly from iron, manganese, or inclusions) — mineral

Tumbled purple agate (likely grape agate or amethystine chalcedony)

Microcrystalline quartz, SiO₂; purple coloration commonly from iron, manganese, or inclusions

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Pale blue-gray quartz-rich pebble (tentative) (Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment) — mineral

Pale blue-gray quartz-rich pebble (tentative)

Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment

Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper

Microcrystalline Quartz (SiO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Jasper (Silicon dioxide (Microcrystalline quartz, SiO2)) — mineral

Jasper

Silicon dioxide (Microcrystalline quartz, SiO2)

Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper

Microcrystalline Quartz (SiO2)

Anthracite Coal (Carbon (with trace impurities)) — sedimentary

Anthracite Coal

Carbon (with trace impurities)

Quartz Pebble (with Hematite/Feldspar Inclusions) (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble (with Hematite/Feldspar Inclusions)

Silicon Dioxide (SiO2)

Coal (Bituminous / Anthracite) (Carbonaceous Sedimentary Rock (C)) — sedimentary

Coal (Bituminous / Anthracite)

Carbonaceous Sedimentary Rock (C)

Sandstone (Sandstone (SiO2-dominated clastic rock)) — sedimentary

Sandstone

Sandstone (SiO2-dominated clastic rock)

Black Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Black Chert

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Limonite (Iron Ore) (Limonite (mixture of hydrated iron(III) oxide-hydroxides)) — Mineral

Limonite (Iron Ore)

Limonite (mixture of hydrated iron(III) oxide-hydroxides)

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

Chert / Flint

Silicon Dioxide (SiO2)

Chert (and Fossilized Brachiopod shell) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

Drupa Quartz (Sparkly Drusy Quartz on Matrix) (Crystalline Silicon Dioxide (SiO2) on host rock) — mineral

Drupa Quartz (Sparkly Drusy Quartz on Matrix)

Crystalline Silicon Dioxide (SiO2) on host rock

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Calligraphy Stone (Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)) — sedimentary

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)

Limonite (Iron Ore) (Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

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

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Common Opal/Chalcedony mixture) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Common Opal/Chalcedony mixture)

Silicon Dioxide (SiO2)

Dalmation Stone (Dalmation Jasper) (Peralkaline rock (primarily Feldspar and Quartz with Arfvedsonite spots)) — igneous

Dalmation Stone (Dalmation Jasper)

Peralkaline rock (primarily Feldspar and Quartz with Arfvedsonite spots)

Chert (Jasper variation) (Chert (Cryptocrystalline microcrystalline Silicon Dioxide, SiO2)) — sedimentary

Chert (Jasper variation)

Chert (Cryptocrystalline microcrystalline Silicon Dioxide, SiO2)

Chert (Jasper) (Silicon dioxide (SiO2)) — sedimentary

Chert (Jasper)

Silicon dioxide (SiO2)

Greenstone Pebble (Metabasalt / Greenschist) — metamorphic

Greenstone Pebble

Metabasalt / Greenschist

Sandstone (Sedimentary Rock (Quartz arenite)) — sedimentary

Sandstone

Sedimentary Rock (Quartz arenite)

Jasper and Basalt Pebble (Polymineralic lithic pebble) — igneous and sedimentary

Jasper and Basalt Pebble

Polymineralic lithic pebble

igneous and sedimentary

Sandstone (Clastic Sedimentary Rock) — sedimentary

Sandstone

Clastic Sedimentary Rock

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

River Pebble (Lithified clastic sediment) — sedimentary

River Pebble

Lithified clastic sediment

Fossil Coral (Rugosa or Tabulata coral fossil (Calcium Carbonate, CaCO3)) — fossil

Fossil Coral

Rugosa or Tabulata coral fossil (Calcium Carbonate, CaCO3)

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble (Silicon dioxide (SiO2)) — mineral

Quartz pebble

Silicon dioxide (SiO2)