Petrified Wood
Silicified wood (principally SiO2)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (principally SiO2)
Tumbled prehnite (probable)
Prehnite, Ca₂Al₂Si₃O₁₀(OH)₂; possibly epidote- or chlorite-bearing
Kyanite
Kyanite, Al₂SiO₅
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Limonite with Hematite
Hydrated iron(III) oxide-hydroxide with variable composition (FeO(OH)·nH2O)
Red Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Chert (variations like Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Black tourmaline (schorl)
Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (and/or Chalcedony)
Microcrystalline Silica (SiO2)
Chrysocolla in Cuprite (Sonoran Sunrise)
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O) (Chrysocolla) and Cu2O (Cuprite)
Chert (Chalcedony/Jasper)
Microcrystalline Quartz (SiO2)
Yellow Chert (Chert / Cryptocrystalline Quartz)
Silicon Dioxide (SiO2)
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline silica (SiO2) with trace Iron oxide (Fe2O3)
Chert (Cherty Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Lichen)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert / Flint
Chert (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Silicon Dioxide (SiO2)
Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
Malachite
Malachite (Cu2CO3(OH)2)
Jasper (specifically Yellow Jasper and Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Flint
Silicon dioxide (SiO2) - cryptocrystalline quartz
Jasper
Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)
Chert (Light Grey / Flint variant)
Cryptocrystalline Quartz (SiO2)
Amber
Succinite (with formula approximately C10H16O)
Pyrite
Iron Sulfide (FeS2)
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Epidote
Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); commonly occurring as an epidote-rich rock
Epidosite (Epidote-rich rock)
Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Pyrite
Iron Disulfide (FeS2)
Quartz (milky variety)
SiO2 (Silicon Dioxide)
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Chert Nodule / Flint
Microcrystalline Quartz (SiO2)