Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (specifically Chert Nodule/Flint)
Chert (Silicon Dioxide, SiO2)
Picture Jasper
Silicon Dioxide (SiO2) - Opaque Chert/Quartzite variety
Chert (Jasper/Common Opal transition)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
Banded Chert
Microcrystalline silicon dioxide (SiO2)
Chert / River Pebble
Microcrystalline Silica (SiO2)
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (C10H16O)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Chert (Chert Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Pink Opal
Hydrated Silicon Dioxide (SiO2 · nH2O)
Petrified Wood
Silicified Wood (SiO2)
Pyrite-bearing Schist
Pyritic Quartz-Mica Schist with FeS2 inclusion
Pyrite
Iron Sulfide (FeS2)
Petrified Wood
Silicified Wood (primarily SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Green Calcite
Calcium Carbonate (CaCO3)
Arid Sandy Loam
Arenosols / Regosols
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Precious Opal
Hydrated silica (SiO2·nH2O)
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
Jasper
Silicon dioxide (SiO2)
Quartz (Milky/Snow)
Silicon Dioxide (SiO2)
Chert (with Calcite Veining)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) veins
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Chert (Nodule / Geode fragment)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (with Liesegang Banding)
Microcrystalline quartz (SiO2)
Chert (Hag Stone / Hole Stone)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Yellow Chert (Yellow Jasper)
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Banded Chert (or Flint)
Microcrystalline Quartz (SiO2)