Petrified Wood
Silicified Wood (SiO2)
sedimentary
Category
Organic Mineral
Browse organic mineral specimens identified by the Rock Identifier community.
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Dragon Stone
Ohko Stone (Argillaceous sedimentary rock)
sedimentary
Likely petrified wood or silicified fossil fragment
Silicified wood; predominantly microcrystalline quartz (SiO₂)
fossil
Paper (Cellulose)
Cellulose (C6H10O5)n
Organic (Anthropogenic)
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Opalite
Synthetic Opalised Glass
Mineral (Synthetic / Man-made)
Amber
Succiniferous organic material (Succinite)
fossil
Petrified Coral (Agatized Coral)
Fossilized Anthozoa (Silicon Dioxide replacement - SiO2)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Seashell Fossil
Invertebrate fossil (phylum Mollusca)
fossil
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
sedimentary
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
sedimentary/mineral
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
Mineral / Fossil
Fossiliferous Limestone (Shell Fragment)
Biogenic Limestone (Calcium Carbonate / CaCO3)
sedimentary
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
mineral (biogenic silica/calcium carbonate substrate)
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Yellow Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Calcium carbonate matrix with macrofossils (CaCO3)
fossil
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Petrified Wood (Silicified Wood)
fossil
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
sedimentary
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
sedimentary
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Lepidodendron Fossil (Scale Tree)
Lepidodendron
fossil
Fossilized Shark Tooth (Fragment)
Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)
fossil
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
fossil
Petrified Wood
Silicon Dioxide Fossilized Wood (SiO2)
fossil
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Petrified Wood
Silicified wood (principally SiO2)
sedimentary
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Blue Quartzite (Dyed)
Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)
metamorphic
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
sedimentary
Petrified Wood
Silicified wood (Quartz replacement)
fossil
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
sedimentary
Fossil-bearing ironstone or weathered concretion
Indeterminate; likely ferruginous sandstone/concretion containing a partial fossil impression
fossil
Possible fossilized ammonite or concretion
Indeterminate fossil specimen; possibly an ammonoid mold/cast in iron-rich sedimentary rock
fossil
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic