Mineral Or Sedimentary (If Chert)

Quartz Crystal Fragment

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky/Crystalline fragment)

Silicon Dioxide (SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host

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)

Concretion

Various mineral compositions, typically carbonate or iron oxide cemented sediment

Sandstone (Quartz Sandstone)

Arenite (primarily SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Botryoidal Chalcedony Geode

Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

Sandstone

Arenite (clastic sedimentary rock)

Gneiss (with Quartzite and Mica)

Gneiss

Quartz

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Banded)

Clastic Sedimentary Rock: Arenite

Shale (sub-type: Carbonaceous Shale)

Lutaceous Sedimentary Rock

Bauxite

Bauxite (mixture of hydrous aluminum oxides: Al(OH)3 & AlO(OH))

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Sandstone with Magnetite and Iron Staining

Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)

Sandstone (with banding)

Arenite (primarily SiO2)

Epidote

Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Quartz Geode (partially formed)

Silicon Dioxide (SiO2)

Limonite/Goethite Concretion

Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)

Gneiss

Gneiss

Quartz (Granular)

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Shale or Mudstone

Argillaceous sedimentary rock

Gneiss

Foliated Metamorphic Rock

Dalmatian Jasper / Dalmatian Stone

Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)

Biotite Gneiss

Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)

Banded Gneiss

Gneiss (Metamorphic Rock)

Quartz

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Sandstone

Arenite (SiO2 principal)

Jasper

Silicon dioxide (SiO2) with impurities

Chalcedony in Limestone Host Rock

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Leopard Skin Jasper

Jasper (Silicon Dioxide with impurities), SiO2