Chert (Green variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Category
Organic (Anthropogenic)
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary
Jasper
Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
sedimentary
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
sedimentary
Stromatolite (Jasper-replaced)
Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
sedimentary
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
sedimentary
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Sea Glass (Kelly Green)
Amorphous Silica (Silicon Dioxide with Iron/Chromium additives)
Anthropogenic specimen (Man-made material)
Sea Glass (specifically Frosted White)
Amorphous Silica (substance: Sodium-calcium silicate glass)
Mineraloid (Anthropogenic/Man-made rock)
Iron Slag
Vitreous glassy waste (Fe-Si-Al-Ca compounds)
Mineral byproduct (anthropogenic / techno-fossil)
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Yellow Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions
sedimentary
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
metamorphic
Fossil Coral (Favosites Honeycomb)
Favosites (Genus), Phylum Cnidaria, Class Anthozoa
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with impurities of Hematite or Goethite
sedimentary
Septarian Nodule
Septarian Concretion
sedimentary
Chert (White/Light Tan)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (Nodular)
Chert (SiO2 - Microcrystalline Quartz)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
sedimentary
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Glauconitic Sandstone (or Greensand)
Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Green Jasper (with Quartz veining)
Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2
sedimentary