What is Cobalt?
Cobalt is a metallic, ferromagnetic element, designated Co on the periodic table. Though not as well known as precious metals like gold, silver, or platinum, it has a remarkable white coloration to it and a superior strength that makes it very valuable for cobalt jewelry and other items. It is also very hard, highly ductile, and moderately malleable, as well as one of only three metals on Earth that are naturally magnetic.
The word “cobalt” comes from the word “kobold”, a German term describing a small, goblin-like creature said to haunt mines and other subterranean domains. Miners in the Harz Mountains took to giving this name to the poisonous rock they would often find. This rock was laced with arsenic and sulfur, and it would make those who were exposed to it very ill. However, it was later discovered that a valuable metal could be extracted from these same rocks. Though this new metal lacked the harmful qualities of the raw material it came from, the name “cobalt” stuck.
Though the first known isolation of cobalt occurred in 1735, it has evidently been used since ancient times in the creation of jewelry and artwork. Small amounts of cobalt can be found in the glass, ceramics, and glazes of ancient Egyptian, Persian, and Chinese artifacts, which accounts for the beautiful blue coloration found therein.
Cobalt is highly rare, with a 0.001 percent occurrence in the Earth’s crust. A majority of the world’s cobalt comes from the Democratic Republic of the Congo, followed by China, Finland, Zambia, and Australia. Most of it is derived in trace quantities from mining operations devoted to different metals, particularly copper and nickel, though it can also be found in meteoric metals.
In addition to its use in cobalt jewelry and decorative items, the metal is also in high demand for medical applications and lithium batteries.
Cobalt jewelry is a great alternative to jewelry made from platinum, white gold, or similar precious metals.
When cobalt is used in jewelry, it generally comes in the form of cobalt chrome. This is an alloy that consists largely of cobalt and chromium, with trace amounts of other metals mixed in. Though not pure cobalt, the alloy retains much of the metal’s more desirable qualities, which include its strength, appearance, hypoallergenic properties, and affordability.
Cobalt is a very hard metal, ranking a five on the Mohs Scale of Mineral Hardness. This puts it high above gold and silver, which rank between 2.5 and 3. Even platinum only ranks between 4 and 4.5. Combined with the metal’s high level of ductility and moderate malleability, this makes cobalt jewelry extremely shatterproof, scratch-resistant, and crack-resistant.
Jewelry made from cobalt chrome has the same lustrous white appearance of platinum or white gold. Also, while white gold will gradually lose its white coloration and need to be re-finished, cobalt chrome will retain its appearance for as long as you have the piece.
Compared to other alternative metals, cobalt chrome has a superior whiteness over both tungsten and titanium.
Can you be allergic to cobalt?
Cobalt has been used for decades to create medical implants. This is because it is highly compatible with the human body. This is good news for the many people who have an allergic reaction to the nickel or other elements found in certain gold and silver rings.
In spite of cobalt’s rarity and superior properties, you can generally expect cobalt jewelry to be much more affordable than equivalent pieces made from platinum or white gold. Though the specific price difference is going to be dependent upon many factors, you may be able to find cobalt chrome pieces at less than half the cost of a similar precious metal piece.