Carnelian (Carnelian Agate)
Carnelian (Silicon Dioxide - SiO2)
Category
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
Carnelian (Carnelian Agate)
Carnelian (Silicon Dioxide - SiO2)
Druzy Quartz on Sandstone
Silicon Dioxide (SiO2) with Quartz crystals
Sandstone
Arenite
Green Kyanite
Kyanite (Al2SiO5)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Shungite
Non-crystalline carbon (allotrope of carbon)
Chert Pebble (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Titanium Coated Aura Quartz (Apple Aura Quartz)
Silicon Dioxide (SiO2) with Metallic Vapor Deposition Coating
Biotite Schist with Garnet
Garnet-Biotite Schist
Common Opal
Hydrated amorphous form of silica (SiO2·nH2O)
Gneiss
Metamorphic rock of high-grade regional metamorphism
Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Sandstone or Siltstone
Arenite (if sandstone)
Sandstone
Arenite (primarily SiO2)
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Sandstone (with potential iron-oxide staining)
Arenite (primarily SiO2)
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is cryptocrystalline quartz). Chemical Formula: SiO2 with inclusions of crocidolite fibers.
Quartz (Clear/White)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (predominantly SiO2 – Silicon Dioxide, but non-crystalline)
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
Riverstone Jasper (Chert variant)
Silicon Dioxide (SiO2)
Red Sandstone
Sandstone (mainly SiO2 with Iron Oxide cement)
Magnetite (potentially Hematite-rich)
Magnetite (Fe3O4)
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Seraphinite
Clinochlore (a variety of the chlorite group)
Jasper with Agate Inclusions
Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate
Native Copper within Host Rock
Native Copper (Cu)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Calamites (Fossil)
Calamites sp. (Tracheophyta, Equisetopsida)
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 with inclusions)
Ironstone Concretion (Moqui Marble Type)
Goethite/Hematite-cemented Sandstone Concretion
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
Quartz Geode
Silicon Dioxide (SiO2)
Chalcedony (Agate/Quartz pebble)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Gold Nugget
Native Gold (Au)
Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)