Galena
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It is often associated with the minerals sphalerite, calcite and fluorite.
Occurrence
Galena is the main ore of lead, used since ancient times, since lead can be smelted from galena in an ordinary wood fire. In some deposits the galena contains up to 0.5% silver, a byproduct that far surpasses the main lead ore in revenue. In these deposits significant amounts of silver occur as included silver sulfide mineral phases or as limited silver in solid solution within the galena structure.
Australia is world's leading producer of lead as of 2021, most of which is extracted as galena. In the United States, it occurs most notably as lead-zinc ore in the Mississippi Valley type deposits of the Lead Belt in southeastern Missouri, which is the largest known deposit, and in the Driftless Area of Illinois, Iowa and Wisconsin, providing the origin of the name of Galena, Illinois, a historical settlement known for the material. Galena is also an important ore mineral in the silver mining regions of Colorado, Idaho, Utah and Montana. Of the latter, the Coeur d'Alene district of northern Idaho was most prominent.
Practical uses
One of the oldest uses of galena was in the eye cosmetic kohl. In Ancient Egypt, this was applied around the eyes to reduce the glare of the desert sun and to repel flies, which were a potential source of disease.
In pre-Columbian North America, galena was used by indigenous peoples as an ingredient in decorative paints and cosmetics, and widely traded throughout the eastern United States. Traces of galena are frequently found at the Mississippian city at Kincaid Mounds in present-day Illinois.
Galena is a semiconductor with a small band gap of about 0.4 eV, which found use in early wireless communication systems. It was used as the crystal in crystal radio receivers, in which it was used as a point-contact diode capable of rectifying alternating current to detect the radio signals. The galena crystal was used with a sharp wire, known as a "cat's whisker" in contact with it.
Spiritual uses
Galena is a strong grounding stone. It can be utilized to open the root chakra, assisting with a grounding connection to the earth. As a dense, heavy stone, galena radiates this same energy, providing balance and focus. Galena can be a good mineral to have nearby during meditation or yoga. It will help condense energy toward you as you work with the natural earth energies.
It is the primary mineral of the Egyptian decanal god Pehuy Djat.