Chert (Yellow Jasper/River Pebble)
Microcrystalline Quartz (SiO2)
Category
Browse granite specimens identified by the Rock Identifier community.
Chert (Yellow Jasper/River Pebble)
Microcrystalline Quartz (SiO2)
Basalt
Extrusive mafic igneous rock
Magnetite (Lodestone)
Magnetite (Fe3O4)
Sandstone
Arenite (SiO2 based with various cements)
Coral Fossil (Favosites)
Favosites (Calcite/Calcium Carbonate, CaCO3)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Dalmatian Jasper (Dalmatian Stone)
Peralkaline rhyolite
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
Chert Pebble
Microcrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Limonite and Goethite on Gossan
FeO(OH)·nH2O
Chert (Commonly known as Flint or River Pebble)
Microcrystalline Quartz (SiO2)
Chert (often called Flint when dark)
Microcrystalline silicon dioxide (SiO2)
Tiger's Eye
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Sandstone (Quartzite Pebble)
Arenite (SiO2)
Iceland Spar (Optical Calcite)
Calcite (Calcium Carbonate, CaCO3)
Chert (Field Stone)
Chert (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Quartz Pebble (Water-Worn)
Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Gold Nugget
Native Gold (Au)
Sandstone (Red)
Arenite (Fe2O3 heavy)
Zebra Jasper
Silicon Dioxide (SiO2) with various inclusions
Basalt (tumbled/water-worn)
Extrusive mafic igneous rock
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
Gold
Native Gold (Au)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
River Stone (Chert/Siltstone)
Cryptocrystalline Quartz (SiO2) with trace impurities
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2)
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Gold Nugget
Native Gold (Au)
Basalt (Crushed Stone Aggregate)
Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)
Gray Agate with Druzy Quartz Geode
Cryptocrystalline Quartz (SiO2)
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Diamond
Diamond (pure carbon C)
Amethyst
Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities