Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
sedimentary
Category
Mineraloid (Organic)
Browse mineraloid (organic) specimens identified by the Rock Identifier community.
Chert (Yellow variety / Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (often called Flint)
Chert (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Green Chert
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Chert with Quartz Veining
Silicon Dioxide (SiO2)
sedimentary
Mosasaur Tooth Fossil
Mosasaurid vertebrate fossil (Hydroxyapatite)
mineral
Chert (variations include Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
sedimentary
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Basanite / Flint)
Microcrystalline silica (SiO2)
sedimentary
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Basanite / Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Fossiliferous)
Silicon dioxide (SiO2)
sedimentary
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline quartz (SiO2)
sedimentary
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
sedimentary
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Chert (specifically as a lithic artifact/projectile point)
Chert (Silicon dioxide, SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
mineral
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Slag (Industrial Glass Slag)
Amorphous Silicate Glass (often containing Al, Ca, Mg, and Ti oxides)
Mineraloid (Industrial byproduct)
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Mineraloid (Man-made)
Green Slag
Anthropogenic Silicate Glass
Mineraloid (Industrial byproduct)
Synthetic Resin (Artificial Specimen)
Polyurethane or Polyester Resin
mineraloid (man-made)
Shell Cameo
Cypraecassis rufa (Bullmouth Queen Helmet Shell)
mineraloid / biogenic specimen