Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
sedimentary
Category
Anthropogenic (Man Made Material Processed By Nature)
Browse anthropogenic (man made material processed by nature) specimens identified by the Rock Identifier community.
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Chert / Flint
Microcrystalline quartz (SiO2)
sedimentary
White Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Chert (Brown Chert / Flint)
Silicon Dioxide (SiO2)
sedimentary
Jasper and Agate (Polychrome Jasper / Mookaite variety)
Silicon dioxide (SiO2) microcrystalline quartz
sedimentary
Plum Blossom Tourmaline
Tourmaline with Lepidolite (Na,Ca)(Li,Mg,Al)3Al6(BO3)3Si6O18(OH)4
igneous
River Stone (likely Quartzite or Sandstone)
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Yellow quartz, possibly citrine
Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz
mineral
Fossilized Shark Tooth
Chondrichthyes (Class)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Mixed Polished Gemstones (Tumbled Stones)
Mixed Silicates and Oxides (SiO2, KAlSi3O8, Ca2Al2Be3Si6O22, etc.)
mineral
Serpentine
Serpentinite (group of minerals based on (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
metamorphic
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
fossil
Banded Flint (Chert)
Silicon Dioxide (SiO2)
sedimentary
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Quartz Pebble (Water-worn)
Silicon Dioxide (SiO2)
mineral
Granite Sand (Decomposed Granite)
Grus / Quartz-Feldspar Detritus
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2 based)
sedimentary
Petrified Wood / Red Jasper
Silicified wood (primarily Silicon Dioxide, SiO2)
sedimentary
Mica schist
Mica schist (Muscovite and Biotite group)
metamorphic
Greenstone / Greenschist
Greenschist (composed of Chlorite, Epidote, and Actinolite)
metamorphic
Iron Slag
Vitreous glassy waste (Fe-Si-Al-Ca compounds)
Mineral byproduct (anthropogenic / techno-fossil)
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Serpentine
Antigorite, Lizardite, or Chrysotile; Mg3Si2O5(OH)4
metamorphic
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Igneous
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Mineral
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Mineral
Shark Tooth Fossil
Otodus obliquus (or similar prehistoric lamniform shark tooth)
fossil
Chert (Flint Nodule)
Microcrystalline and Cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth
Elasmobranchii dentition (calcium phosphate / hydroxyapatite)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
mineral
Petrified Wood
Silicified Wood (primarily Quartz or Chalcedony, SiO2)
mineral
Red Sandstone
Arenite (primarily Quartz with Iron Oxide)
sedimentary
Chert (often called Flint)
Chert (Microcrystalline Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Serpentine
Serpentine group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al)2O5(OH)4)
metamorphic
Honey calcite (orange calcite)
Calcite, calcium carbonate (CaCO₃)
mineral