Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Stromatolite (Fossiliferous Limestone) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Stromatolite (Fossiliferous Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Pearl (Calcium Carbonate (primarily Aragonite and Calcite), CaCO3) — mineral

Pearl

Calcium Carbonate (primarily Aragonite and Calcite), CaCO3

Chert (variously identified as Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (variously identified as Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Flint variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossilized Crab Carapace (Concretion) (Decapoda (fossil), typically preserved in calcite or siderite concretion) — sedimentary

Fossilized Crab Carapace (Concretion)

Decapoda (fossil), typically preserved in calcite or siderite concretion

Chert Arrowhead (Projectile Point) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (SiO2)

Glauconitic Sandstone (Greensand) (Glauconitic quartz wacke or arenite) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic quartz wacke or arenite

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

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

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Chalcedony (Agatized Coral / Rough Chalcedony Node) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agatized Coral / Rough Chalcedony Node)

Silicon Dioxide (SiO2)

Moqui Marbles (Iron Oxide Concretion (Hematite/Goethite)) — sedimentary

Moqui Marbles

Iron Oxide Concretion (Hematite/Goethite)

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

Chert (Chert Nodule in Limestone)

Microcrystalline Quartz (SiO2)

Gray Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Gray Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper when red) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (often called Flint or Jasper when red)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Field Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically a flint nodule component) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically a flint nodule component)

Microcrystalline quartz (SiO2)

Chert (often called Flint) (Chert (Microcrystalline or cryptocrystalline Silica, SiO2)) — sedimentary

Chert (often called Flint)

Chert (Microcrystalline or cryptocrystalline Silica, SiO2)

Chert (specifically Red Chert or Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Red Chert or Jasper)

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified wood (primarily SiO2)

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

Chert (Pink Jasper)

Microcrystalline Quartz (SiO2)

Chert Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert (Field Stone) (Chert (SiO2)) — sedimentary

Chert (Field Stone)

Chert (SiO2)

Chert (Tan/Brown) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (Tan/Brown)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert / Flint (Chert (SiO2)) — sedimentary

Chert / Flint

Chert (SiO2)

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

Chert (Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Iron-stained variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained variant)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Anthracite Coal (Anthracite) — metamorphic

Anthracite Coal

Anthracite

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Shungite (Non-crystalline carbon (similar to anthracite coal or meta-anthracite)) — metamorphic

Shungite

Non-crystalline carbon (similar to anthracite coal or meta-anthracite)

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

Black Jasper

Jasper (Silicon Dioxide, SiO2)

Ironstone Concretion (Siderite or Hematite Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite Concretion

Fossiliferous Limestone (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Petrified Dinosaur Bone (Gembone) (Agatized Dinosaur Bone) — sedimentary

Petrified Dinosaur Bone (Gembone)

Agatized Dinosaur Bone

Fossil Coral (Rugose Coral Fragment) (Rugosa (extinct order of solitary and colonial corals)) — sedimentary

Fossil Coral (Rugose Coral Fragment)

Rugosa (extinct order of solitary and colonial corals)