Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Chert Pebble
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
SiO2 (Silicon Dioxide) with Fe2O3 (Hematite)
Chert (Flint)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Basanite / Flint variety)
Microcrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert / Lake Superior Agate
Cryptocrystalline Silicon Dioxide (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone with Coral Imprint
Fossiliferous Limestone (CaCO3)
Shale with Iron Staining
Fissile Mudrock (Sedimentary Rock)
Chert / Flint
Chert (SiO2)
Amber
Fossilized Tree Resin (Succinate)
Angel Skin Coral
Corallium rubrum / Corallium spp. (Calcium Carbonate, CaCO3)
Quartz and Limestone Grouping
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)
Galena
Lead(II) sulfide (PbS)
Gold
Native Gold (Au)
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite impurities
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Gneiss
Gneiss (High-grade metamorphic rock)
Fossiliferous Limestone
Biogenic Sedimentary Rock
River Pebble (Siltstone/Mudstone)
Clastic sedimentary rock
Amethyst Cluster Pendant
Silicon Dioxide (SiO2) - Quartz variety Amethyst
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Limonite inclusions
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper with Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz
Silicon dioxide (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression)
Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)
Limestone
Calcium Carbonate (CaCO3)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Chlorite or Actinolite
Weathered flint or chert fragment
Microcrystalline quartz (SiO₂), likely chert/flint
Chalcedony / Agate with Botryoidal Quartz
Silicon Dioxide (SiO2)
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)