Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse sedimentary (secondary classification: cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Jasper or Chalcedony
Microcrystalline Quartz (SiO2)
Pyrite
Iron Disulfide (FeS2)
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Orange Quartzite (River Pebble)
Quartzite (primarily SiO2)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with varying mineral impurities
Grey Chalcedony (Tumbled)
Chalcedony (SiO2)
Quartz (Common Quartz Pebble)
Silicon Dioxide (SiO2)
Sandstone (likely Calcareous or Micaceous)
Clastic sedimentary rock (primarily Quartz with Cementing Agents)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
Red Jasper (River Polished)
Silicon Dioxide (SiO2) with Hematite impurities
Jasper (likely Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with impurities
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Quartz
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Quartz Geode (River Cobble)
Silicon Dioxide (SiO2)
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide with Hematite impurities (SiO2 + Fe2O3)
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
Quartz (likely milky/gray variety)
Quartz (SiO₂)
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Carnelian Agate
Silicon Dioxide (SiO2) with Iron Oxide impurities
Milky Quartz (Crystal Cluster)
Silicon Dioxide (SiO2) - Quartz Variety
Kambaba Jasper (Crocodile Jasper)
Stromatolitic Rhyolite/Jasper (SiO2)
Gold Nugget
Native Gold (Au)
Gold Ore
Native Gold (Au)
Pyrite in Matrix (likely Quartz or Coal)
Iron Sulfide (FeS2)
Jasper
Silicon dioxide (SiO2) with impurities
Red Jasper (Chert)
Silicon Dioxide (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (Nodule)
Chert (SiO2)
Dinosaur Bone (Gembone)
Petrified Dinosaur Bone (Apatite/Silica replacement)
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)