Chert (Common Variety)
Cryptocrystalline Quartz (SiO2)
Category
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Chert (Common Variety)
Cryptocrystalline Quartz (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
Blue Quartzite
Quartzite with inclusions (SiO2)
Bivalve Fossil (Clam)
Class Bivalvia (Calcium Carbonate, CaCO3)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Ferruginous Sandstone
Arenite with Iron-Oxide cement (Fe2O3 · nH2O)
Chert with Desert Varnish
Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating
Jasper Breccia
Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Chert (often called Flint)
Chert (Microcrystalline Quartz, SiO2)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Yellow Quartz (Citrine appearance)
Silicon Dioxide (SiO2)
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
Quartz with Iron Oxide Monzonite or Sandstone contact
Quartz (SiO2) with Limonite/Hematite staining
Quartz Geode
Silicon Dioxide (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Sandstone (Weathered Cobble)
Clastic Sedimentary Rock (primarily SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Jasper (River pebble)
Jasper / Silicon Dioxide (SiO2)
Black Tourmaline in Quartz
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) in Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide with traces of titanium, iron, or manganese (SiO2)
Granite Pebble
Granite (composed primarily of Quartz, Feldspar, and Mica)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Chert (SiO2)
Amethyst (Rough Crystal)
Silicon Dioxide (SiO2 with ferric iron impurities)
Chert (River Pebble)
Chert (SiO2)
Artificial Rock Face (Faux Rock)
Glass Fiber Reinforced Concrete (GFRC)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Lapis Lazuli
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite and other associated minerals)
Agate (specifically Waterline or Onyx-type Agate)
Silicon Dioxide (SiO2) - variety Chalcedony
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Banded Sandstone
Arenite with Liesegang banding
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Green Fluorite in Host Rock
Fluorite (Calcium Fluoride, CaF2)
Chert (Jasper/Chalcedony variety)
Silicon Dioxide (SiO2)
Chert (Heart-shaped Pebble)
Cryptocrystalline quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
Chatoyant Quartz (Cat's Eye Quartz)
Silicon Dioxide (SiO2) with fibrous inclusions of Amphibole or Rutile
Sandstone (Ferruginous)
Arenite (with Hematite/Limonite cement)