Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (often called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (and Limestone Pebbles)
Silicon Dioxide (SiO2) / Sedimentary Microcrystalline Quartz
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
Yellow Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Biotite Schist
Biotite Schist
Jasper
Microcrystalline Quartz (SiO2)
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Dyed Agate
Chalcedony (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Quartz Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Milky Quartz / Rose Quartz fragment
Silicon Dioxide (SiO2)
Jasper (Iron-rich)
Silicon Dioxide (SiO2) with Fe2O3 (Hematite) impurities
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
Nile Agate
Silicon Dioxide (SiO2)
Gold
Gold (Au)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Diorite (or Gabbro/Granitoid)
Diorite
Fluorite
Calcium Fluoride (CaF2)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Gold Nugget
Native Gold (Au)
Green Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
Fuchsite (Green Muscovite)
K(Al,Cr)2(AlSi3O10)(OH)2
Gold Nugget
Native Gold (Au)
Gold Flakes
Native Gold (Au)
Lepidolite in Quartz (Obelisk)
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lepidolite)
Granite
Phaneritic plutonic rock (Felsic)
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Chert Pebble
Microcrystalline or cryptocrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Bull Quartz with Mica and Host Rock
Massive Quartz (SiO2) with Muscovite/Chlorite inclusions
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Green Banded Chert (Agate/Jasper)
Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite
Rhodonite
Rhodonite (Manganese silicate), (Mn,Fe,Mg,Ca)SiO3
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Red Jasper (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
Agate
Silicon dioxide (Chalcedony), SiO2