Petrified Wood
Silicified Wood (SiO2)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Yellow Chalcedony (Tumbled/Cabochon)
Silicon dioxide (SiO2)
Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
Lake Superior Agate
Chalcedony (Microcrystalline Quartz, SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Geode (Unopened)
Siliceous Concretion / Geode
Red Sandstone
Sandstone (mainly SiO2 with Iron Oxide cement)
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Flint / Chert Pebble
Microcrystalline quartz (SiO2)
Flint
Cryptocrystalline quartz (SiO2)
Flint / Chert
Microcrystalline quartz (SiO2)
Flint
Silicon dioxide (Cryptocrystalline Quartz, SiO2)
Flint / Chert
Microcrystalline Quartz (SiO2)
Chert (Flint / Quartz Nodule)
Microcrystalline Quartz (SiO2)
Sandstone (Wonderstone)
Arenite (composed primarily of SiO2 with Fe2O3 impurities)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement) SiO2
Chert
Microcrystalline Quartz (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Gneiss with Quartz Veining
Gneiss (High-grade metamorphic rock)
Iron-rich sandstone (Gozan/Ironstone)
Ferruginous Sandstone (clastic sedimentary rock)
Petrified Wood
Silicified wood / Permineralized wood (SiO2)
Sandstone
Sedimentary Rock (Quartz Arenite)
Gneiss with Quartz Vein
Gneiss containing Quartz (SiO2) filler
Fossil Bivalve Shell
Class Bivalvia (e.g., Veneriidae family)
Granitic Gneiss
Gneiss (Metamorphic rock of granitic composition)
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
Chert / Flint Nodule
Cryptocrystalline quartz (SiO2)
Chert / Flint
Microcrystalline quartz (SiO2)
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Chert (Jasper/Pebble)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Chert (Nodular flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Gneiss
Foliated quartzo-feldspathic gneiss, commonly containing biotite or amphibole
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Sandstone
Sandstone (clastic sedimentary rock)
Petrified Wood
Silicified Wood (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Conglomerate
Conglomerate
Fossilized Bivalve Shell (Fossilized Clam)
Bivalvia (class) / CaCO3 (Calcium Carbonate)