Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

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

Amber (Succinite (fossilized resin)) — mineral

Amber

Succinite (fossilized resin)

Coal (specifically Bituminous or Anthracite) (Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N) — sedimentary

Coal (specifically Bituminous or Anthracite)

Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N

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

Chert (Flint)

Microcrystalline silica (SiO2)

Pyrite (Fool's Gold) Cube (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold) Cube

Iron Sulfide (FeS2)

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

Flint (Chert)

Silicon Dioxide (SiO2)

Limestone (River Pebble) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (River Pebble)

Calcium Carbonate (CaCO3)

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Jasper Agate (Silicon dioxide (SiO2)) — mineral

Jasper Agate

Silicon dioxide (SiO2)

Red Coral (with Hematite and Black Pearl accents) (Corallium rubrum (Calcium Carbonate, CaCO3)) — mineral

Red Coral (with Hematite and Black Pearl accents)

Corallium rubrum (Calcium Carbonate, CaCO3)

Chalcedony (Common Opal variant) (Silicon dioxide (SiO2) with varying levels of hydration) — mineral

Chalcedony (Common Opal variant)

Silicon dioxide (SiO2) with varying levels of hydration

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Pearl and Garnet Glass (Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass) — mineral and glass

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

mineral and glass

Shale (Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)) — sedimentary

Shale

Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)

Precious Red Coral (Corallium rubrum / Corallium japonicum) — mineral (organic gemstone)

Precious Red Coral

Corallium rubrum / Corallium japonicum

mineral (organic gemstone)

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)

Amber (Succinite (C10H16O)) — mineraloid

Amber

Succinite (C10H16O)

Petrified Wood (Silicified Wood) (Silicified fossil wood (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified fossil wood (SiO2)

Amber (Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)) — Organic Mineraloid

Amber

Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)

Organic Mineraloid

Epidote (or Epidote-rich rock) (Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).) — Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks

Amber (Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)) — Mineraloid

Amber

Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)

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

Flint

Chert (Silicon dioxide, SiO2)

Mother of Pearl and Onyx (Aragonite (Mother of Pearl) and Chalcedony (Onyx)) — mineral

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)) — mineral

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Pyritized Ammonite (Ammonitida (replaced by Iron Disulfide, FeS2)) — sedimentary

Pyritized Ammonite

Ammonitida (replaced by Iron Disulfide, FeS2)

Amber (Succinite (fossilized resin); C10H16O) — mineraloid

Amber

Succinite (fossilized resin); C10H16O

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Graphite (Graphite (Native Carbon), Formula: C) — Metamorphic

Graphite

Graphite (Native Carbon), Formula: C

Pyrite in Matrix (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite in Matrix (Fool's Gold)

Iron Disulfide (FeS2)

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

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

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Petrified Wood (Silicified wood (Quartz, Chalcedony, or Opal)) — sedimentary

Petrified Wood

Silicified wood (Quartz, Chalcedony, or Opal)

Amber (Succinite (Resinite)) — Organic Crystal (Mineraloid)

Amber

Succinite (Resinite)

Organic Crystal (Mineraloid)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Chert (containing small fossils) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (containing small fossils)

Chert (Microcrystalline Quartz, SiO2)

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

Chert / Flint

Silicon Dioxide (SiO2)

Graphite (Graphite (Carbon, C)) — metamorphic

Graphite

Graphite (Carbon, C)

Chert (and Chalcedony) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Chalcedony)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Agatized Fossil (Druzy Agate) (Silicon Dioxide (SiO2) replacing organic matter) — sedimentary

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

Petrified Wood (Silicified Fossil) (Silicified Wood (SiO2)) — sedimentary

Petrified Wood (Silicified Fossil)

Silicified Wood (SiO2)