Rock Identifier

Category

Organic (Often Found By Beachcombers)

Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.

Pink Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Pink Opal

Hydrated Silica (SiO2·nH2O)

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

Yellow Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (Pebble) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (Pebble)

Chert (Microcrystalline Quartz, SiO2)

Pearl (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Chert (Jasper variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper-like Silicate) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper-like Silicate)

Microcrystalline quartz (SiO2)

White Coral (Corallium rubrum (biocarbonate calcium) / CaCO3) — mineral

White Coral

Corallium rubrum (biocarbonate calcium) / CaCO3

Baltic Amber (Butterscotch or Egg Yolk Variety) (Succinite (C10H16O)) — Organic Gemstone (Mineraloid)

Baltic Amber (Butterscotch or Egg Yolk Variety)

Succinite (C10H16O)

Organic Gemstone (Mineraloid)

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

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

Amber (Succinite (fossilized tree resin)) — mineraloid / sedimentary organic material

Amber

Succinite (fossilized tree resin)

mineraloid / sedimentary organic material

Amber (Succinite (specifically for Baltic amber); chemical formula approximately C10H16O) — Mineraloid

Amber

Succinite (specifically for Baltic amber); chemical formula approximately C10H16O

Pearls (Aragonite (calcium carbonate) and Conchiolin) — Mineraloid

Pearls

Aragonite (calcium carbonate) and Conchiolin

Asphalt (Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)) — Sedimentary

Asphalt

Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)

Chert (Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (Pebble)

Microcrystalline silica (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint/Novaculite) (Chert (formula: SiO2)) — sedimentary

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Pearl (Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3) — mineral

Pearl

Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3

Chert (and Quartz Gravel) (Chert (Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (and Quartz Gravel)

Chert (Cryptocrystalline Quartz, SiO2)

Shale or Argillite (Shale (sedimentary) / Argillite (metamorphic)) — Sedimentary or Metamorphic (low-grade)

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Sedimentary or Metamorphic (low-grade)

Chert (Quartz Variety) (Chert (SiO2)) — sedimentary

Chert (Quartz Variety)

Chert (SiO2)

Chert (Jasper/Flint Pebble) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint Pebble)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Fossiliferous Limestone (Limestone (CaCO3 - Calcium Carbonate)) — sedimentary

Fossiliferous Limestone

Limestone (CaCO3 - Calcium Carbonate)

Petrified Wood (Silicified Wood (primarily Chalcedony or Quartz, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Petrified Wood (Calamites Fossil) (Calamites sp. (Silicified/Permineralized Plant Fossil)) — sedimentary

Petrified Wood (Calamites Fossil)

Calamites sp. (Silicified/Permineralized Plant Fossil)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Petrified Wood (Silicified wood, primarily composed of Quartz (SiO2)) — Mineral, often found in sedimentary deposits

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Mineral, often found in sedimentary deposits

Orthoceras Fossil in Limestone (Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone) — sedimentary

Orthoceras Fossil in Limestone

Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Pearl (Aragonite and Conchiolin (CaCO3 + organic protein)) — mineraloid

Pearl

Aragonite and Conchiolin (CaCO3 + organic protein)

Natural or Cultured Pearl (Calcium Carbonate (Aragonite and Conchiolin), CaCO3) — Mineral (Organic)

Natural or Cultured Pearl

Calcium Carbonate (Aragonite and Conchiolin), CaCO3

Mineral (Organic)

Pearl (Aragonite / Calcium Carbonate (CaCO3)) — mineral

Pearl

Aragonite / Calcium Carbonate (CaCO3)

River Stone (Chert/Siltstone) (Cryptocrystalline Quartz (SiO2) with trace impurities) — sedimentary

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

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

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Flint (Chert)

Silicon Dioxide (SiO2)

Chert (specifically Gray/Tan Chert Node) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray/Tan Chert Node)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

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

Chert (specifically Jasper/Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (White Chert or Flint) (Microcrystalline or cryptocrystalline quartz (SiO2)) — sedimentary

Chert (White Chert or Flint)

Microcrystalline or cryptocrystalline quartz (SiO2)