Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (with Iron Staining) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Iron Staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ammonite Fossil (Ammonoidea (Calcium carbonate - CaCO3)) — sedimentary

Ammonite Fossil

Ammonoidea (Calcium carbonate - CaCO3)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Petoskey Stone (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Chert (and Flint) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (and Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (specifically Black Chert or Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Black Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically a fragment with Desert Varnish) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically a fragment with Desert Varnish)

Microcrystalline quartz (SiO2)

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

Chert (and Limestone)

Silicon Dioxide (SiO2)

Chert (Grey Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Grey Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz, SiO2)) — metamorphic

Petrified Wood

Silicified wood (Quartz, SiO2)

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

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Crinoid Fossil in Limestone (Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)) — sedimentary

Crinoid Fossil in Limestone

Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)

Limestone (Porous/Travertine variant) (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

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

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Tufa (Calcareous Tufa (Calcium Carbonate, CaCO3)) — sedimentary

Tufa

Calcareous Tufa (Calcium Carbonate, CaCO3)

Fossilized Megalodon Tooth Fragment (Otodus megalodon (Carcharocles megalodon fossil)) — sedimentary

Fossilized Megalodon Tooth Fragment

Otodus megalodon (Carcharocles megalodon fossil)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)

Black Jasper (Black Stone / River Pebble) (Silicon Dioxide (SiO₂), Opaque variety of Chalcedony) — sedimentary

Black Jasper (Black Stone / River Pebble)

Silicon Dioxide (SiO₂), Opaque variety of Chalcedony

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Chert (often called Flint or Jasper) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (White-Tan variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (White-Tan variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Arenicola (comprising mostly Quartz, SiO2)) — sedimentary

Sandstone

Arenicola (comprising mostly Quartz, SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO₂)

Amber (Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O) — Organic mineraloid

Amber

Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O

Organic mineraloid

Jasper (Green/Yellow Moss Jasper) (Silicon Dioxide (SiO2)) — mineral

Jasper (Green/Yellow Moss Jasper)

Silicon Dioxide (SiO2)

Ferruginous Sandstone (Ironstone) (Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)) — sedimentary

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Moss Agate (Silicon Dioxide (SiO2) with inclusions) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Diamond in Gold Setting (Diamond (C - pure carbon)) — mineral

Diamond in Gold Setting

Diamond (C - pure carbon)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Fossiliferous Brachiopod in Shale (Brachiopoda (Phylum) preserved in Carbonaceous Shale) — sedimentary

Fossiliferous Brachiopod in Shale

Brachiopoda (Phylum) preserved in Carbonaceous Shale

Chert (Field Stone) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Field Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper with Quartz Vein (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Petrified Wood (Silicified Wood) (Silicified Wood / Silicon Dioxide (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified Wood / Silicon Dioxide (SiO2)

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

Chert / Flint

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood / Chalcedony (SiO2)) — mineral

Petrified Wood

Silicified Wood / Chalcedony (SiO2)

Chert (Jasper/Mudstone) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Mudstone)

Silicon Dioxide (SiO2)

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

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint variant)

Microcrystalline Quartz (SiO2)