Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
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Chert or chalcedony nodule
Microcrystalline quartz (SiO₂), possibly weathered chert
mineral
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
fossil
Fossilized bivalve shell fragment
Fossil Mollusca, likely a pectinid or related bivalve; exact identification requires the other shell half and locality
fossil
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Stardust (Micrometeorite)
Chondrite / Micrometeorite (Extraterrestrial Silicate)
igneous
Agatized Fossil Coral
Agatized Anthozoa
fossil
Petrified wood
Silicified fossil wood, commonly quartz/chalcedony (SiO₂) replacing woody tissue
fossil
Amygdaloidal Basalt with Agate/Quartz Infill
Basalt with Secondary Silicate Mineralization (SiO2)
igneous
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
sedimentary
Likely bituminous coal
Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image
sedimentary
Chalcedony (Agate/Seashell replacement)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary
Fossil Shark Tooth
Elasmobranchii tooth fossil (e.g., Otodus / Carcharocles)
fossil
Fossiliferous Flint
Microcrystalline Quartz (SiO2) with Echinoid Fossil
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Rhodonite
Manganese Silicate (MnSiO₃)
mineral
Polished red gemstone beads, possibly garnet
Unconfirmed; likely almandine garnet (Fe₃Al₂(SiO₄)₃)
gemstone
Fossilized bone fragment
Petrified bone, mineral-replaced vertebrate bone; exact taxon indeterminate
fossil
Blue-green copper mineral specimen, likely chrysocolla-bearing rock
Chrysocolla, hydrated copper silicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with quartz or turquoise
mineral
Dinosaur Fossil (Skull)
Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)
sedimentary
Fossilized Shark Tooth (Fragment)
Elasmobranchii fossil (likely Cretalamna or Squalicorax genus)
sedimentary
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Tektite
Natural impact glass
meteorite
Polished fossilized wood (likely petrified wood)
Silicified wood; primarily quartz (SiO₂) replacing wood tissue
fossil
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Red faceted gemstone, possibly garnet
Likely almandine garnet, Fe₃Al₂(SiO₄)₃; identity cannot be confirmed from the image
gemstone
Fossil Shark Tooth Fragment
Elasmobranchii dentition (fragment)
fossil
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Tumbled chert or flint pebble
Microcrystalline quartz (SiO₂), likely chert; exact variety uncertain from the image
sedimentary
Unakite
Epidotized Granite
metamorphic
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
sedimentary
Petrified Wood
Silicified Wood (Permineralized organic tissue)
fossil
Flint (chert) with chalcedony/quartz
Microcrystalline quartz, SiO₂; likely flint or siliceous chert with a chalcedonic edge
sedimentary
Graphite
Graphite (Carbon, C)
mineral
Quartz-rich river pebble (likely milky quartz or quartzite)
Quartz, SiO₂; possibly quartzite, a metamorphic rock dominated by quartz
mineral
Yellow jasper-like chalcedony
Microcrystalline quartz (SiO₂), likely iron-stained jasper or chert
mineral