Moss Agate
SiO2 (Cryptocrystalline Quartz)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Moss Agate
SiO2 (Cryptocrystalline Quartz)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Chert
Microcrystalline Quartz (SiO2)
Red Jasper
Microcrystalline quartz (SiO2) with iron oxide impurities
Green Calcite
Calcium Carbonate (CaCO3)
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2)
Freshwater Pearl
Aragonite / Biogenic Calcium Carbonate (CaCO3)
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
Jasper
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Chert (Cherty Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (containing Calcite or Quartz inclusions)
Silicon Dioxide (SiO2) with varying mineral impurities
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert (varietal Flint)
Chert (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) - Limestone
Green Jasper
Silicon Dioxide (SiO2) with impurities
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Common Opal/Agatized Rock)
Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica
Jasper
Silicon dioxide (SiO2) with impurities
Chert (specifically Novaculite or Porcelainite)
Microcrystalline to Cryptocrystalline Quartz (SiO2)
Amber
Succinite
Black Chert (Flint)
Microcrystalline Quartz (SiO2)
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Fluorite in Host Rock
Calcium Fluoride (CaF2)
Blue Calcite
Calcium Carbonate (CaCO3)
Banded Chert
Chert (Silicon Dioxide, SiO2)
Coquina / Shelly Sandstone
Calcareous Sandstone / Coquina
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Greenstone / Graywacke
Metagraywacke or Chlorite Schist
Native Copper (Penny specimen)
Native Copper (Cu)
Celestine (or Celestite)
Strontium sulfate (SrSO4)
Gneiss (specifically Amphibolite Gneiss)
Gneiss
Chert (River Siltstone/Quartzite)
Sedimentary Cryptocrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)