Heidi Krebbs, age 12, of Miami, Florida, for her question:
WHO DISCOVERED PLATINUM?
Platinum is a precious, silver white metal that is even more valuable than gold. An Italian scientist named Julius Scaligar discovered the metal in 1557.
But fairly large quantities of platinum were not discovered until about 1750 when the Spaniards found it in Peru. They named the metal platinum for their word plata, meaning silver.
The ore, called native or crude platinum, usually occurs in beds of gold bearing sand. Miners call it white gold.
Nativeplatinum contains from 60 to 85 percent pure platinum. The small, irregular grains that contain the ore also contain other rare metals, such as iridium,osmium, palladium, rhodium and ruthenium.The grains also contain small amount of iron, copper, chromium and titanium.
Occasionally a large nugget of native platinum will be found. In1843, a lump weighing more than 21 pounds was found in Russia. Russia produces the largest share of the world's platinum group metals. Other important sources of platinum are in the Transvaal province in South Africa and in Sunbury, Ontario, Canada. Colombia and the United States also have sources of platinum.
The United States uses about 660,000 troy ounces of platinum each year. About one sixth comes from its own mines and from scrap. The rest must be imported.
In the United States, platinum occurs in the gold bearing deposits in California, Nevada and Oregon.A large amount also comes from the process of refining gold and copper.
Platinumcan be shaped and worked in almost every possible way. It can be drawn into fine wire,or it can be hammered into thin sheets. It does not corrode or tarnish when exposed to air because it does not combine readily with oxygen or sulfur compounds found in air. Strong acids that dissolve most metals do not attack platinum.
Chemical laboratories. often use platinum containers because the metal resists heat and chemicals. For the same reason, platinum parts are sometimes used in large scale production equipment.
Platinum serves as an effective catalyst, a substance that speeds up chemical reactions. Automobile manufacturers use platinum in an emission control device called a catalytic converter. The platinum helps to convert certain harmful pollutants into nonpollutants.
The oil industry also uses platinum to help break down fractions or partsof petroleum to produce gasoline of higher octane number. Platinum is also used as a catalyst in making various chemicals, such as acetic acid and nitric acid.
Platinumis a favorite material for use in expensive jewelry. Its strength, hardness,color and freedom from tarnish make it ideal for gem settings.Platinum is also used on the best surgical instruments.
Analloy of platinum with iridium makes an excellent surface for fine engravings. The same alloy makes standards of weights and measures, contact points with electrical equipment and the tips of fountain pens. Platinum salts are used in some photographic prints.