Chert (Brown Variety)
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.
Amazonite
Amazonite (K(AlSi3O8))
mineral
Rhodonite in Quartz Matrix
Rhodonite (Manganese Iron Magnesium Calcium Silicate - Mn,Fe,Mg,Ca)SiO3
mineral
Yellow Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)
metamorphic
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sunstone
Oligoclase (Plagioclase Feldspar) - (Ca,Na)(Al,Si)4O8
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Ruby in Kyanite
Al2O3 (Corundum) in Al2SiO5 (Kyanite-Fuchsite-Quartz)
metamorphic
Limonite (Iron Ore)
Limonite (unstructured hydrated iron(III) oxide-hydroxides, often FeO(OH)·nH2O)
mineral
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
mineral
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Chert
Silicon dioxide (SiO2)
Sedimentary
Petrified Wood (Silicified Wood)
Silicified fossil wood (SiO2)
metamorphic
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Galena
Lead Sulfide (PbS)
mineral
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Jasper or Chert
Silicon Dioxide (SiO2)
sedimentary
Fluorite (likely Fluorite on Quartz/Matrix)
Calcium Fluoride (CaF2)
mineral
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
mineral
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
sedimentary
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Banded Jasper with Hematite or Quartz
Silicon Dioxide (SiO2) with impurities
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron impurities
mineral
Chert (Chalcedony/Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Nodule)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Agate (specifically a small Chalcedony nodule)
Agate (Cryptocrystalline variety of Quartz, SiO2)
mineral
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
sedimentary (microcrystalline quartz)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Ferruginous Sandstone (Ironstone)
Sedimentary rock with high iron oxide content (Fe2O3 / FeO(OH))
sedimentary
Amber (Copal)
Succinite (fossilized tree resin)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
mineral
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (with potentially high Feldspar/Arkose content)
Clastic sedimentary rock (SiO2 dominated)
sedimentary