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.

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

Chert (Arrowhead or Projectile Point)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Red Jasper (Silicon Dioxide (SiO2) with Hematite inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Pyrite and Sunstone (Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)) — mineral

Pyrite and Sunstone

Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)

Cullet Glass (Slag Glass) (Amorphous Silicon Dioxide (Industrial Byproduct)) — mineraloid

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial Byproduct)

Lazulite (Magnesium Aluminum Phosphate Hydroxide (MgAl2(PO4)2(OH)2)) — mineral

Lazulite

Magnesium Aluminum Phosphate Hydroxide (MgAl2(PO4)2(OH)2)

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Sphalerite in Matrix (Polished Point) (Zinc sulfide (Zn,Fe)S) — mineral

Sphalerite in Matrix (Polished Point)

Zinc sulfide (Zn,Fe)S

Travertine (Travertine (CaCO3 - Calcium Carbonate)) — sedimentary

Travertine

Travertine (CaCO3 - Calcium Carbonate)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Jasper (Cryptocrystalline Quartz (SiO2)) — sedimentary

Jasper

Cryptocrystalline Quartz (SiO2)

Carnelian (Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)) — mineral

Carnelian

Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)

Tumbled Carnelian and Quartz Mix (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Tumbled Carnelian and Quartz Mix

Silicon Dioxide (SiO2) with iron oxide impurities

Quartz (Iron-stained or Milky) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-stained or Milky)

Silicon Dioxide (SiO2)

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

Chert (Flint Nobule)

Silicon Dioxide (SiO2)

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

Peridot (Olivine)

Olivine ((Mg, Fe)2SiO4)

Sodalite (Sodalite [Na8(Al6Si6O24)Cl2]) — mineral

Sodalite

Sodalite [Na8(Al6Si6O24)Cl2]

Rutilated Quartz (Quartz with Rutile inclusions (SiO2 with TiO2 inclusions)) — mineral

Rutilated Quartz

Quartz with Rutile inclusions (SiO2 with TiO2 inclusions)

Unakite Pebble (Epidotized Granite) — metamorphic

Unakite Pebble

Epidotized Granite

Granite (Granite (a felsic intrusive igneous rock)) — igneous

Granite

Granite (a felsic intrusive igneous rock)

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Carnelian (Carnelian (Silicon Dioxide - SiO2)) — mineral

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)) — mineral

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Beryl (likely Emerald or Aquamarine in matrix) (Beryllium aluminum silicate (Be3Al2Si6O18)) — mineral

Beryl (likely Emerald or Aquamarine in matrix)

Beryllium aluminum silicate (Be3Al2Si6O18)

Puddingstone (Jasper Conglomerate) (Conglomerate (specific type: Jasper Conglomerate or Hertfordshire Puddingstone)) — Sedimentary

Puddingstone (Jasper Conglomerate)

Conglomerate (specific type: Jasper Conglomerate or Hertfordshire Puddingstone)

Coal (Bituminous or Anthracite coal (carbon-rich sedimentary rock)) — sedimentary

Coal

Bituminous or Anthracite coal (carbon-rich sedimentary rock)

Sandstone (Quartzose) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (Arenite (Sedimentary rock composed of sand-sized minerals or rock grains)) — sedimentary

Sandstone

Arenite (Sedimentary rock composed of sand-sized minerals or rock grains)

Sandstone (Ferruginous) (Arenite (with Iron Oxide)) — sedimentary

Sandstone (Ferruginous)

Arenite (with Iron Oxide)

Unidentifiable Rock Fragment — Uncertain

Unidentifiable Rock Fragment

Quartz (likely macrocrystalline variety) (Quartz (SiO₂)) — Mineral

Quartz (likely macrocrystalline variety)

Quartz (SiO₂)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Sandstone (Quartzose) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Smoky Quartz (Silicon Dioxide (SiO2) with aluminum impurities) — mineral

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Amethyst (Amethyst (Silicon Dioxide, SiO2 with Iron impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

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

Peridot

Olivine ((Mg, Fe)2SiO4)

Dalmatian Stone (Dalmatian Jasper) (Dalmatian Stone (A variety of Perthite / Aplite)) — Igneous

Dalmatian Stone (Dalmatian Jasper)

Dalmatian Stone (A variety of Perthite / Aplite)

Quartz (Smoky Quartz variant) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Chert (potentially Flint or Mudstone) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (potentially Flint or Mudstone)

Microcrystalline Quartz (SiO2)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)