Carnelian
SiO2 (Silicon Dioxide), a variety of Chalcedony
Category
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
Carnelian
SiO2 (Silicon Dioxide), a variety of Chalcedony
Green Calcite
Calcium Carbonate (CaCO3)
Hematite
Iron(III) oxide (Fe2O3)
Pyrite (on host rock/ore)
Iron Sulfide (FeS2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Pyrite (Fool's Gold) Ore
Iron Disulfide (FeS2)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
Plume Agate
Silicon Dioxide (SiO2)
Selenite (Satin Spar Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Hematite
Iron(III) oxide (Fe2O3)
Sandstone with Iron Concretion
Arenite with Limonite/Goethite Concretion
Banded Agate
Cryptocrystalline Quartz (SiO2)
Turquoise (Green variety)
Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Clear Quartz
Silicon Dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Biotite Gneiss
Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)
Sandstone (Ferruginous)
Arenite (with high iron oxide content)
Sandstone
Arenite (primarily SiO2)
Fluorite
Calcium fluoride (CaF2)
Quartz Geode (partially formed)
Silicon Dioxide (SiO2)
Gneiss (with Quartzite and Mica)
Gneiss
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
Petrified Wood
Silicified Wood (primarily SiO2)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Geode (Unbroken)
Silicon Dioxide (SiO2) usually as Microcrystalline Quartz or Chalcedony
Jasper with Iron Staining
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)
Gneiss (specifically Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)
Jasper
Silicon dioxide (SiO2) with impurities
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)