Mineral Health

Citrine (Yellow Quartz)

Silicon Dioxide (SiO2)

Unidentified polished mineral specimen

Indeterminate; likely a pale feldspar or quartz-bearing material

Greenstone (likely chlorite- or actinolite-rich metabasalt)

Metamorphosed mafic volcanic rock; commonly greenschist-facies basalt, composed chiefly of chlorite, actinolite, epidote, and albite

Rounded dark-gray rock, likely diorite or andesite

Probable diorite (plagioclase and hornblende/pyroxene); identification is limited by the image

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Granite pebble

Granite; predominantly quartz, feldspar, and mica

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Red garnet crystal cluster

Most likely almandine garnet, Fe₃Al₂(SiO₄)₃; exact species cannot be confirmed from the image alone.

Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Gneiss (River Cobble)

Gneiss

Lapis Lazuli

Na6Ca2(Al6Si6O24)(S,SO4,Cl)1-2 (primarily containing Lazurite with inclusions of Calcite and Pyrite)

Gneiss (specifically Banded Gneiss)

Gneiss

Fluorite (Rainbow, Purple-Blue Tumbled)

Calcium Fluoride (CaF2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Basalt with Secondary Mineralization (Likely Zeolites or Calcite)

Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)

Granite

Phaneritic Felsic Igneous Rock

Rounded granite pebble

Granite, a quartz–feldspar–mica plutonic rock

Tumbled Mixed Gemstones and Rocks

Various mineral species including quartz (SiO2) and silicate minerals

Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Green glass-like mineral specimen, likely fluorite

Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass

Quartz Mineral

Silicon dioxide (SiO2)

Quartz Mineral

Silicon Dioxide (SiO2)

Quartz Mineral

Silicon Dioxide (SiO2)

Limonite (Ironstone)

Limonite (FeO(OH)·nH2O)

Weathered copper-bearing rock, possibly chrysocolla-bearing quartz or host rock

Indeterminate from the photo; possible chrysocolla (hydrated copper silicate) with quartz or other host minerals

Quartz Mineral

Silicon Dioxide (SiO2)

Gold Mineral

Native Gold (Au)

Travertine

Calcium Carbonate (CaCO3)

Limonite (Yellow Ochre)

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

Limonite (Iron Ore)

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

Granite

Intrusive igneous felsic rock

Turquoise

Turquoise, CuAl6(PO4)4(OH)8·4H2O

Milky quartz cluster

Quartz, silicon dioxide (SiO₂)

Sandstone with Manganese Dendrites

Clastic Sedimentary Rock (SiO2 based with MnO2 inclusions)

Pink-purple rough mineral specimen (possibly lepidolite-bearing mica)

Lepidolite, a lithium-rich mica; identification is uncertain from the photo

Quartz Vein in Hematitic Siltstone

Hydrothermal Quartz (SiO2) in Ferriferous Matrix

Jade (likely Jadeite)

Jadeite (a pyroxene mineral) or Nephrite (a variety of amphibole mineral)

Yellow iron-oxide-rich mineral/rock fragment

Likely limonite/goethite (hydrated iron oxides; commonly approximated as FeO(OH)·nH₂O)

Likely garnet-bearing rock (possibly almandine garnet in dark matrix)

Garnet, probably almandine (Fe₃Al₂(SiO₄)₃); host rock is not identifiable from this image

Sodalite

Na8Al6Si6O24Cl2

Banded quartz-rich rock (possibly pegmatite)

Likely quartz–feldspar pegmatite; identification is tentative from the photo

Milky quartz (rough quartz specimen)

Quartz, silicon dioxide (SiO₂)