Fulgarite
Fulgurite (Lechatelierite / Vitrified Sand)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Fulgarite
Fulgurite (Lechatelierite / Vitrified Sand)
Fossil-bearing sedimentary rock, possibly fossil wood or bone
Indeterminate silicified/carbonate fossil in sandstone or mudstone
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (often called Jasper or Flint)
Silicon Dioxide (SiO2)
Chert (Jasper-like Silicate)
Microcrystalline quartz (SiO2)
Jasper (specifically a banded or dark variety)
Silicon Dioxide (SiO2) with impurities
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (specifically Flint or Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
Chert (often called Flint or River Rock)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Chert (SiO2)
Chert (Jasper/Flint Pebble)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Volcanic glass (SiO2-rich)
Conglomerate
Conglomerate (clastic sedimentary rock)
Quartz with Mica inclusions (Gold-colored Mica)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (Phlogopite/Muscovite) inclusions
Gastropod Fossil (Snail Steinkern)
Class Gastropoda (internal mold)
Petrified Wood
Silicified Wood (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Quartzite
Quartzite (Primary mineral: SiO2)
Quartzite
Quartzite (SiO2)
Tumbled green gemstone, likely dyed howlite or serpentine
Most consistent with dyed howlite (Ca2B5SiO9(OH)5); exact identification requires testing
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Banded Chert (likely Flint or Jasper variety)
Silicon Dioxide (SiO2)
Green Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (White-Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Chert (White Chert/Flint)
Chert (SiO2)
Yellow Jasper / Chert
Jasper (Silica/Quartz) - SiO2
Fossil Shell (Bivalve)
Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)
Chert with Crinoid Fossil Impression
Microcrystalline Quartz (SiO2) with Crinoidea fossil impression
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Common Chert)
Silicon Dioxide (SiO2)
Moqui Marble (Shaman Stone)
Ironstone Concretion (Goethite/Hematite Shell)