====== Platinum ======
{{wst>image_cl|Patek Philippe|Chronographe Automatique|[[Patek Philippe Annual Calendar Chronograph Ref. 5960P]]\\ in **platinum** case}}

**Platinum** is the most valuable precious metal. The highly corrosion resistant, malleable and soft heavy metal shows, in the pure, polished state, the so-called dark sheen. The name derives from the Spanish word //platina//, the diminutive of plata ("[[silver]]"). (In the late 16th century [[gold]] miners in Colombia had mistaken the white metal for silver.

After platinum was known as early as 1,500 BC in North Africa and South America, it fell into oblivion over a period of 2,000 years and was only used around [[1850]] by [[Cartier, Louis|Louis Cartier]] as jewelry.

Platinum jewelry was especially popular during the [[Art Déco]]. In [[1924]] the German geologist Dr. Hans Merensky discovered west of Johannesburg the largest platinum deposit in the world. Other important deposits are in the Ural Mountains and in Canada.

Throughout the world there are only a few findings of this rare metal. For a single ounce of montain platinum (31.1 g) approximately ten tons of ore must be mined.

Platinum is stronger, tougher and heavier than other jewelry metals. Its melting point is at 1,774°C, compared to gold with 1,064°C. Therefore its processing is extremely costly and especially tough machines and tools have to be used.

Platinum is mainly processed with a [[fineness]] of 950/000 (that is cleaner than the usual [[gold]] alloys).

Allergic reactions are not known. Thus, the precious metal is ideal as a pin, which is led through the earlobe with ear plugs.

===== Literature =====
  *[[Das ZEITGEFÜHL-Uhrenbuch]]; Author [[Gerd-Lothar Reschke]]; ISBN 3-938607-61-0


{{tag>Terms Watch_materials}}