Shale
Shale (clay-sized silicate minerals)
sedimentary
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Learn about Mineral (Silicate Replaced Organic Material) in the encyclopedia
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Silicified Gastropod Fossil (Agatized Fossil)
Gastropoda (Class) preserved in Chalcedony/Quartz (SiO2)
sedimentary
Chert / Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide staining)
sedimentary
Chert (often called Flint or Jasper locally)
Chert (Microcrystalline Quartz, Formula: SiO2)
sedimentary
Chert with Limestone Cortex
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Tiger's Eye (Jasper-like Chalcedony)
Silicon dioxide (SiO2) - Pseudomorph after Crocidolite
metamorphic
Unakite
Epidotized Granite (Fe, Ca, Al silicate + KAlSi3O8)
metamorphic
Zircon
Zirconium Silicate (ZrSiO₄)
mineral
Sandstone
Arenite
sedimentary
Fossilized Shark Teeth
Otodus sp. (Eocene Sand Tiger/Mackerel Shark)
fossil
Mosasaur Tooth Fossil
Mosasauridae (likely Prognathodon or Mosasaurus)
fossil
Pyrite
Iron Sulfide (FeS2)
mineral
Green Jasper (with Quartz veining)
Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2
sedimentary
Pink Rhodonite
Manganese Silicate (MnSiO3)
mineral
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper / Chert (Red)
Cryptocrystalline quartz (SiO2)
Sedimentary / Mineral
Fossil Shell (Brachiopod or Mollusk)
Phylum Brachiopoda or Class Bivalvia (e.g., Mucrospirifer or similar genus)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Yellow Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions
sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
metamorphic
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Fossilized Gastropod Shell
Class Gastropoda (Fossil)
sedimentary
Chalcedony (Agate/Seashell replacement)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Slag (Industrial Byproduct)
Anthropogenic Vitreous Silicate material
igneous
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
mineral
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
sedimentary
Planet Earth
Gaia (Silicate Terrestrial Planet)
metamorphic
Petrified Wood
Silicified Wood (primarily Silicon Dioxide, SiO2)
mineral
Tiger's Eye (Multicolor/Variegated)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
mineral
Turritella Agate (Fossiliferous Chert)
Silicified Elimia tenera (Fossiliferous Chalcedony)
sedimentary
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
sedimentary
Green Calcite (often commercially called Green Onyx)
Calcium Carbonate (CaCO3)
Mineral
Blue Topaz
Al2SiO4(F,OH)2
mineral
Limonite with Trace Fossils
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Amygdaloidal Basalt with Epidote
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Charoite
Charoite (Complex silicate mineral rock)
metamorphic
Petrified Bone Pebble
Silicified Fossilized Bone
fossil
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Sandstone
Arenite
sedimentary