Because of its hardness, the diamond is the most enduring of all gemstones. They are among the most costly jewels in the world, partly because they are rare, Only four important diamond fields have been found - in Africa, South America, India, and the Soviet Union. In 1957, the Shippingport Atomic Power Station in Pennsylvania, the first nuclear facility to generate electricity in the United States, went on line. In 1982, in the first operation of its kind, doctors at the University of Utah Medical Center implanted a permanent artificial heart in the chest of retired dentist Dr. Barney Clark, who lived 112 days with the device. Mercury is the only metal that is liquid at room temperature.
Natural gas has no odor.
The smell is added artificially so that leaks can be detected. Prussic acid, in a crystalline powder called Zyklon B, was used to kill in Germany's gas chambers. The gas would paralyze the victim's lungs, causing them to suffocate. Sea water, loaded with mineral salts, weighs about a pound and a half more per cubit foot than fresh water at the same temperature. The Chinese were using aluminum to make things as early as 300 AD Western civilization didn't rediscover aluminum until 1827.