Chert (River Pebble)
Silicon Dioxide (SiO2)
sedimentary
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
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Fossiliferous Limestone (Coral Fossil)
Scleractinian Coral in Calcium Carbonate (CaCO3)
sedimentary
Chert with Quartz Veining
Silicon Dioxide (SiO2)
sedimentary
Dinosaur Fossil Tooth
Vertebrate Fossilized Tooth
fossil
Malachite
Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)
Mineral
Chert (specifically Gray/Blue Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Unakite
Unakite (Epidotized Granite)
metamorphic
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
mineral
Chert (or Flint)
SiO2 (predominantly microcrystalline quartz)
Sedimentary
Amazonite
KAlSi3O8 (Potassium Aluminum Silicate) - a variety of Microcline Feldspar
mineral
Bituminous Coal
Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
sedimentary
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
sedimentary
Tumbled brown jasper
Microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained
sedimentary
Amber
Succiniferous organic material (Succinite)
fossil
Amber
Succinited (C10H16O)
fossil
Amber
Succinite (Fossilized Tree Resin)
mineraloid
Shark Tooth Fossil
Otodus sp. (possibly Cretalamna)
fossil
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
fossil
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Red Sandstone
Ferruginous Sandstone (SiO2 dominated with Fe2O3 cement)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Shark Tooth Fossil
Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)
fossil
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
mineraloid
Jasper Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth (Otodus)
Otodus sp. (calcium phosphate/hydroxylellite)
sedimentary
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (variously known as Flint or Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
gemstone
Coprolite
Coprolite (fossilized feces)
sedimentary
Chert (Flint/Jasper variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Limestone/Flint variant)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral