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.

Amber (Succinite (with approximate formula C10H16O)) — mineraloid

Amber

Succinite (with approximate formula C10H16O)

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcedony replacement)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcedony replacement)

Mineral / Fossil

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Carnelian (Carnelian (Silicon Dioxide - SiO2 with Hematite impurities)) — Mineral

Carnelian

Carnelian (Silicon Dioxide - SiO2 with Hematite impurities)

Quartz (Silicon Dioxide (SiO₂)) — Mineral

Quartz

Silicon Dioxide (SiO₂)

Banded Gneiss (Gneiss (typically quartz, feldspar, mica, amphibole composition)) — metamorphic

Banded Gneiss

Gneiss (typically quartz, feldspar, mica, amphibole composition)

Agate (or Chalcedony) (SiO2 (Silicon Dioxide) - a cryptocrystalline variety of quartz) — Mineral

Agate (or Chalcedony)

SiO2 (Silicon Dioxide) - a cryptocrystalline variety of quartz

Garnet (Almandine) (Almandine (Fe3Al2(SiO4)3)) — metamorphic

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Red Jasper (Red Jasper (SiO2 with Fe2O3 impurities)) — sedimentary

Red Jasper

Red Jasper (SiO2 with Fe2O3 impurities)

Jade (likely Nephrite Jade based on appearance) (Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)) — Mineral

Jade (likely Nephrite Jade based on appearance)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)

Diorite (Diorite (intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (intermediate intrusive igneous rock)

Chert (Jasper) (Microcrystalline Quartz (SiO2) with iron oxide impurities) — sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

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

Petrified Wood (Silicified Fossil)

Silicified Wood (SiO2)

Hematite (Hematite (Fe2O3)) — Mineral

Hematite

Hematite (Fe2O3)

Diorite (or salt-and-pepper granite pebble) (Phaneritic Igneous Rock (Intermediate Composition)) — igneous

Diorite (or salt-and-pepper granite pebble)

Phaneritic Igneous Rock (Intermediate Composition)

Pearls (Aragonite (calcium carbonate) and Conchiolin) — Mineraloid

Pearls

Aragonite (calcium carbonate) and Conchiolin

Green Moss Agate (Silicon Dioxide with inclusions (SiO2 + Mn/Fe)) — sedimentary

Green Moss Agate

Silicon Dioxide with inclusions (SiO2 + Mn/Fe)

Pearl (Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)) — mineral

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Chert (Jasper) (Microcrystalline Quartz (SiO2) with Iron Oxide inclusions) — sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2) with Iron Oxide inclusions

Garnet (specifically Almandine) (Almandine (Fe3Al2(SiO4)3)) — mineral

Garnet (specifically Almandine)

Almandine (Fe3Al2(SiO4)3)

Fossiliferous Limestone (CaCO3 (principally Calcite or Aragonite)) — sedimentary

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)

Chert (Iron-stained) (Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Coral Fossil (Scleractinia) (Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)) — sedimentary

Coral Fossil (Scleractinia)

Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)

River Stone (Chert/Siltstone) (Cryptocrystalline Quartz (SiO2) with trace impurities) — sedimentary

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

Chert (with Quartz Veining) (Microcrystalline silicon dioxide (SiO2)) — sedimentary

Chert (with Quartz Veining)

Microcrystalline silicon dioxide (SiO2)

Chert (varieties include Flint and Jasper) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (varieties include Flint and Jasper)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Chert (Jasper/Quartzite river stone) (Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Quartzite river stone)

Microcrystalline Silicon Dioxide (SiO2)

Chert (Chert (SiO2)) — sedimentary

Chert

Chert (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

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

Chert (Quartz Variety)

Chert (SiO2)

Flower Jasper (Agatized Fossil Coral / Chalcedony (SiO2)) — sedimentary

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

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

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (and Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Flint)

Cryptocrystalline Quartz (SiO2)

Carnelian (Flame Polished) (Carnelian (SiO2 with Iron Oxide impurities)) — mineral

Carnelian (Flame Polished)

Carnelian (SiO2 with Iron Oxide impurities)

Pegmatite (with Quartz and Feldspar) (Granitic Pegmatite) — igneous

Pegmatite (with Quartz and Feldspar)

Granitic Pegmatite

Turquoise (Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]) — mineral

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Carnelian Agate (Chalcedony (SiO2) with iron oxide inclusions) — mineral

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

Yellow Quartzite (River Pebble) (Quartzite (primarily Silicon Dioxide, SiO2)) — metamorphic

Yellow Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide, SiO2)

Garden Quartz (Included Quartz (SiO2 with accessory minerals such as Chlorite, Hematite, or Feldspar)) — mineral

Garden Quartz

Included Quartz (SiO2 with accessory minerals such as Chlorite, Hematite, or Feldspar)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)