Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Fossilized Shark Tooth (likely Sand Tiger Shark)
Carcharias taurus (fossilized hydroxyapatite/calcium phosphate)
Fossilized Shark Tooth (Megalodon or Carcharocles fragment)
Elasmobranchii (Fossilized tooth root / crown section)
Petrified Wood
Silicified wood (primarily SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with Iron Oxide inclusions
Chert (and Jasper/Flint variety)
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Green variety)
Silicon Dioxide (SiO2)
Geode (Unopened)
Silica-rich concretion (SiO2)
Chert (Basanite / Jasper)
Microcrystalline quartz (SiO2)
Chert Concretion with Iron Oxide Staining
Microcrystalline Quartz (SiO2)
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
Calcareous Tufa (or Travertine)
Calcium Carbonate (CaCO3)
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Chert (Yellow/Tan variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (Flint/Jasper variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint Pebbles)
Chert (SiO2)
Chert (Jaspery variety)
Microcrystalline Quartz (SiO2)
Chert / Flint
Chert (Cryptocrystalline Quartz, SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (and Limestone)
Chert (consisting of Microcrystalline Quartz, SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (White Chert or Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Orthoceras Fossil Limestone
Orthoceras (extinct Cephalopod fossil) in Matrix
Jasper
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Cryptocrystalline Quartz (SiO2)
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)