The pre-Columbian Indians of South America knew the element platinum. As far as the modern world of chemistry was concerned it was discovered by Antonio de Ulloa in South America in the year 1735. Antonio de Ulloa gave the metal the name platinum from the Spanish word “platina” which means silver as an indication of the color of the metal. It was however described by the Italian Julius Caesar Scaliger in 1557 having seen the metal in Mexico. Scaliger described it as a noble metal “which no fire nor any Spanish artifice has yet been able to liquefy.”
The element has the atomic number 78 and is classified amongst the transitional metals in the periodic table. It density @ 293 K is 21.45 grams per cubic centimeter. Platinum has five naturally occurring stable isotopes.
The metal, in its free state, occurs in gold bearing sands found in Columbia, the Western United States and the Ural mountains. It also occurs in the mineral ore sperrylite in the Sudbury basin area of Ontario, Canada where it is recovered as a by-product of nickel mining. The Sudbury basin is associated with a meteorite impact and platinum has a higher abundance in meteorites and moon rocks than in rocks from Earth. Another platinum containing mineral ore, cooperite, occurs in the mines of the Merensky Reef in South Africa.
The element gives its name to a group of precious metals found within the periodic table. The Platinum Group Metals (PGM) is made up of the elements ruthenium, rhodium, palladium, osmium, iridium, and platinum.
The metal is much valued in the production of jewelry and watches as well as laboratory equipment. Platinum was used to make the coronation crown for Queen Elizabeth, the Queen Mother, when she was crowned as consort to King George the Sixth. Its main usage, however, is as a catalyst in the automobile industry. From 1875 until 1960, the standard rule, used to measure the SI meter, was made of 90% platinum and 10% iridium.
Platinum is extremely rare making up only 0.003 parts per billion of the Earths Crustal rocks. That means it is 30 times rarer than gold. This rarity has led to the term platinum being use to describe the value of such items as credit cards and record sales around the world. It is also traded as bullion with the currency code XPT.
Although originally deriving from the term for silver platinum has now itself become a description of a color as in Platinum Blond describing a particular hair color.