Rock Identifier

Category

Organic Gemstone (Often Associated With Sedimentary Sequences)

Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.

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

Opal

Hydrated Silica (SiO2·nH2O)

Limonite/Goethite on Shale (Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock) — sedimentary

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Chert (variations include Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Ironstone Concretion (Siderite or Hematite Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite Concretion

Lepidolite (Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)) — mineral

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

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

Chert (Gravel)

Microcrystalline Quartz (SiO2)

Peridot (Olivine ((Mg,Fe)2SiO4)) — Mineral

Peridot

Olivine ((Mg,Fe)2SiO4)

Clear Quartz (Quartz (Silicon Dioxide, SiO2)) — Mineral

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

Chert (Nodule / Geode fragment) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Labradorite (Dark or Black variety) (Labradorite (member of Plagioclase Feldspar group), (Na,Ca)(Si,Al)4O8) — mineral

Labradorite (Dark or Black variety)

Labradorite (member of Plagioclase Feldspar group), (Na,Ca)(Si,Al)4O8

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

Petrified Wood

Silicified wood (principally Silicon Dioxide, SiO2)

Chert / Quartz Pebble (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert / Quartz Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (and Flint variant) (Chert (SiO2)) — sedimentary

Chert (and Flint variant)

Chert (SiO2)

Chert (or Flint) (Chert (microcrystalline or cryptocrystalline quartz, SiO2)) — Sedimentary

Chert (or Flint)

Chert (microcrystalline or cryptocrystalline quartz, SiO2)

Fossilized Pycnodonte Oyster (Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)) — sedimentary

Fossilized Pycnodonte Oyster

Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily SiO₂ / Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

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

Crinoid Fossil in Limestone

Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Coral Fossil) (Scleractinian Coral in Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (Coral Fossil)

Scleractinian Coral in Calcium Carbonate (CaCO3)

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

Jasper

Jasper (Silicon Dioxide, SiO2)

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

Chert (Quartz Variety)

Microcrystalline Silica (SiO2)

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

Rhodonite (Manganese Silicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Amber / Copal (Fossilized Tree Resin (Succinate)) — Mineraloid

Amber / Copal

Fossilized Tree Resin (Succinate)

Green Banded Chert (Agate/Jasper) (Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite) — sedimentary

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Chert (and Limestone) River Cobble (Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert (and Limestone) River Cobble

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Amazonite (KAlSi3O8 (Potassium Aluminum Silicate) - a variety of Microcline Feldspar) — mineral

Amazonite

KAlSi3O8 (Potassium Aluminum Silicate) - a variety of Microcline Feldspar

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

Gold (Native Gold (Au)) — mineral

Gold

Native Gold (Au)

Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Pink Lepidolite (Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)) — mineral

Pink Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Carnelian (Red Agate) (Chalcedony (SiO2 with Iron Oxide impurities)) — mineral

Carnelian (Red Agate)

Chalcedony (SiO2 with Iron Oxide impurities)

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

Chert (often called Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (variously known as Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variously known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Amber (Succinite (fossilized tree resin)) — mineraloid

Amber

Succinite (fossilized tree resin)

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

Chert (variations include Flint)

Chert (Silicon Dioxide, SiO2)