Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Shale (Shale) — sedimentary

Shale

Shale

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

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (often called Flint when dark or worked) (Cryptocrystalline silica (SiO2)) — sedimentary

Chert (often called Flint when dark or worked)

Cryptocrystalline silica (SiO2)

Chert (often called Flint or River Pebble) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often called Flint or River Pebble)

Chert (Microcrystalline Quartz, SiO2)

Fossilized Wood (Petrified Wood) (Silicified Wood (primarily quartz/chalcedony replacing organic matter)) — Sedimentary (with some aspects of mineral replacement)

Fossilized Wood (Petrified Wood)

Silicified Wood (primarily quartz/chalcedony replacing organic matter)

Sedimentary (with some aspects of mineral replacement)

Oak-grain Laminate (Industrial/Decorative Furniture Finish) (Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)) — not a rock (synthetic material)

Oak-grain Laminate (Industrial/Decorative Furniture Finish)

Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)

not a rock (synthetic material)

Coquina / Limonite-stained Limestone (Sedimentary Limestone with Iron Oxyhydroxide (FeO(OH)·nH2O)) — sedimentary

Coquina / Limonite-stained Limestone

Sedimentary Limestone with Iron Oxyhydroxide (FeO(OH)·nH2O)

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

Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite

Fossiliferous Limestone (Fossiliferous Limestone (CaCO3)) — sedimentary

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3)

Amber (Succinite (fossilized tree resin)) — mineral

Amber

Succinite (fossilized tree resin)

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

Amber in Matrix

Succinite (Carbon-based organic polymer)

Organic (Sedimentary context)

Moss Agate (Chalcedony (SiO2) with inclusions of manganese or iron oxides) — mineral

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxides

Amber (Succinates (Organic compound: C10H16O)) — mineraloid

Amber

Succinates (Organic compound: C10H16O)

Red Jasper (beads) (SiO₂ (Silicon Dioxide)) — Mineral, variety of chalcedony (microcrystalline quartz)

Red Jasper (beads)

SiO₂ (Silicon Dioxide)

Mineral, variety of chalcedony (microcrystalline quartz)

Stromatolite (Biogenic Sedimentary Rock (composed predominantly of CaCO3)) — sedimentary

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Natural Pearl (appearing in a jewelry setting) (Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin) — mineral

Natural Pearl (appearing in a jewelry setting)

Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin

Chert (Green variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood (SiO2)) — metamorphic

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2)

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

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Shungite (Non-crystalline carbon (high-carbon metamorphic rock)) — metamorphic

Shungite

Non-crystalline carbon (high-carbon metamorphic rock)

Coal (Bituminous or Anthracite) (Carbonaceous sedimentary rock (primarily Carbon, C)) — sedimentary

Coal (Bituminous or Anthracite)

Carbonaceous sedimentary rock (primarily Carbon, C)

Amber (Succinates (Organic Fossilized Resin)) — mineral

Amber

Succinates (Organic Fossilized Resin)

Shungite (Carbonaceous rock (primarily amorphous carbon)) — Mineraloid

Shungite

Carbonaceous rock (primarily amorphous carbon)

Amber / Fossilized Resin (Succinite / Fossilized Tree Resin) — mineral

Amber / Fossilized Resin

Succinite / Fossilized Tree Resin

Fossil Shell (Bivalve) (Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3) — sedimentary

Fossil Shell (Bivalve)

Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3

Chert (often called Flint when dark) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pearl (Organic Mineraloid (CaCO3 + Conchiolin)) — mineral

Pearl

Organic Mineraloid (CaCO3 + Conchiolin)

Dendritic Moss Agate (Chalcedony (Silicon Dioxide, SiO2) with inclusions) — mineral

Dendritic Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with inclusions

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

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

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

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)

Chert (Arrowhead Preform) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Arrowhead Preform)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Shale (Shale (comprised mostly of clay minerals and quartz)) — sedimentary

Shale

Shale (comprised mostly of clay minerals and quartz)

Pearl (likely Freshwater or Akoya Cultured) (Aragonite / Conchiolin composite (CaCO3)) — Mineralloid (Organic gemstone)

Pearl (likely Freshwater or Akoya Cultured)

Aragonite / Conchiolin composite (CaCO3)

Mineralloid (Organic gemstone)

Smurf Rock (Fictional Interpretation) (Cyanus Anthropomorphicus (Geologic Simulation)) — Artificial/Fantasy Object

Smurf Rock (Fictional Interpretation)

Cyanus Anthropomorphicus (Geologic Simulation)

Artificial/Fantasy Object

Shungite (Non-crystalline carbon (allotrope of carbon)) — metamorphic

Shungite

Non-crystalline carbon (allotrope of carbon)

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image) (SiO₂ (silicon dioxide)) — Sedimentary

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

Amber (Organic gemstone (Succinite)) — mineral

Amber

Organic gemstone (Succinite)

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Pearl (Organic Mineral (CaCO3 with conchiolin)) — mineral

Pearl

Organic Mineral (CaCO3 with conchiolin)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)