Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Category
Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material) in the encyclopedia
View all →
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Porphyritic granite or granitic gneiss
Quartz–feldspar–biotite granite; possibly foliated into granitic gneiss
igneous
Wishing Stone with Quartz Vein
Quartz-veined sedimentary pebble
sedimentary
Clear Quartz crystals on a Matrix base (Geode fragment)
Silicon Dioxide (SiO2)
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Conglomerate
Conglomerate
Sedimentary Rock
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pearl
Nacre (Aragonite and Conchiolin), CaCO3
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
White Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
sedimentary
Chalcedony Agate / Carnelian nodules in Matrix
SiO2 (Silicon Dioxide) with iron oxide inclusions
mineral
Petrified Wood
Silicified wood (SiO2)
fossil
Tumbled banded metamorphic stone
Likely banded gneiss or migmatitic gneiss; exact identification requires testing
metamorphic
Aquamarine
Beryl (Be3Al2Si6O18)
mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Blue Apatite
Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Hag Stone
Calcareous sedimentary rock (often Chert, Flint, or Limestone)
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)
Mineral-based Sedimentary/Silica
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
sedimentary
Marble (Sculpted Statue)
Metamorphic Limestone (composed primarily of Calcite, CaCO3)
metamorphic
Precious Red Coral
Corallium rubrum / Corallium japonicum
mineral (organic gemstone)
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Fossil Shark Tooth
Carcharadon sp. (likely Carcharodon carcharias or similar Lamniformes)
fossil
Ruby
Corundum (Aluminium Oxide with Chromium impurities, Al2O3:Cr)
mineral
Quartz with inclusions
Silicon Dioxide (SiO2)
mineral
Banded gneiss
Gneiss, chiefly quartz–feldspar–mica (variable composition)
metamorphic
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Blue Slag Glass
Man-made Silicon Dioxide (Amorphous)
Anthropogenic (Man-made)
Limonite/goethite-rich ironstone
Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O)
mineral
Soapstone
Steatite (composed primarily of Talc: Mg3Si4O10(OH)2)
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
igneous
Petrified Wood
Silicified Wood (SiO2)
Mineral / Fossil
Fossil Shark Tooth
Chondrichthyes (Class)
fossil
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil