Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
fossil
Category
Organic Materia (Not A Rock Or Mineral)
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Petrified Wood
Silicified wood (principally SiO2)
sedimentary
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
sedimentary
Sandstone
Sedimentary rock composed mainly of sand-sized minerals or rock grains
sedimentary
Plume Agate or Moss Agate
Agate (SiO2)
mineral
Granite
Felsic intrusive igneous rock
igneous
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily quartz replacing organic cellulose)
fossil
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Bivalve Seashell Fossil
Class Bivalvia
fossil
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Ironstone / limonite-rich concretion
Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O), possibly with hematite
mineral
Geode (Unopened)
Siliceous Geode (SiO2)
sedimentary
Sandstone (Painted)
Arenite (primarily SiO2)
sedimentary
Granite-like igneous rock
Likely medium-grained granite or granodiorite; quartz–feldspar–mica aggregate
igneous
Druzy Quartz Geode
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Granite Gneiss
Granitic Gneiss
Metamorphic
Quartz (on matrix)
Quartz (Silicon Dioxide, SiO₂)
Mineral
Granite
Phaneritic Felsic Igneous Rock
igneous
Red Sandstone
Sedimentary Clastic Rock (Quartz Arenite)
sedimentary
Granite Cobble
Intrusive Igneous Rock (Felsic to Intermediate)
igneous
Calcite (or Travertine / Limestone)
Calcium Carbonate (CaCO3)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Limestone-based)
Silicon dioxide (SiO2)
sedimentary
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Quartz Crystal Matrix
Silicon Dioxide (SiO2)
mineral
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Petrified Wood
Silicified Wood (SiO2)
fossil
Sandstone with Quartz Vein
Arenite with SiO2 intrusion
sedimentary
Granite
Intrusive Igneous Rock
igneous
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral