Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (Fe2O3)
Category
Browse igneous, sedimentary, and metamorphic specimens identified by the Rock Identifier community.
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (Fe2O3)
Chalcedony (Agate)
Cryptocrystalline Quartz (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
White Agate (Chalcedony)
Agate (Silicon Dioxide - SiO2)
Fluorite
Calcium Fluoride (CaF2)
Carnelian Agate
Carnelian (SiO2 with iron oxide impurities)
Banded Agate (Pink Chalcedony)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
White Quartz Pebbles
Quartz (Silicon Dioxide, SiO2)
Fluorite (Blue)
Calcium Fluoride (CaF2)
Amethyst with Marcasite accents
Amethyst (Silicon Dioxide SiO2) and Marcasite (Iron Sulfide FeS2)
Conglomerate with Quartz Inclusions
Conglomerate (clastic sedimentary rock) with internal Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Moonstone
Orthoclase Feldspar (KAlSi3O8)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Banded Onyx (Green Onyx)
Banded Calcite or Travertine (CaCO3)
Pyrite in Matrix (Commonly called Fool's Gold)
Iron Sulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Grey Chalcedony (Tumbled)
Chalcedony (SiO2)
Hematite
Ferric oxide (Fe2O3)
Chalcedony (Agate/Carnelian precursor)
Chalcedony (Silicon Dioxide, SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Silica, SiO2)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Botryoidal Agate
Chalcedony (Silicon Dioxide, SiO2)
Red Quartz (Carnelian/Red Jasper Agate)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Limonite Pseudomorph after Pyrite
Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Rough Agate/Chert Nodules
Cryptocrystalline Quartz (SiO2)
Red Jasper (Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))
Petrified Wood
Silicified Wood (SiO2)
White Marble
Recrystallized Calcite (CaCO3)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2)
Jasper with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Sorosilicate [Ca2Al2Fe3+Si3O12(OH)]
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
Dalmatian Jasper (or Dalmatian Stone)
Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)
Bi-Color Tourmaline (or Watermelon Tourmaline)
Tourmaline (complex borosilicate mineral group with general formula AD3G6(BO3)3T6O18(OH,O)4)
Jasper
Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)
Red Jasper (Banded Jasper)
Silicon Dioxide (SiO2) with Hematite impurities