Fluorescence gets its name, and spelling, from the mineral fluorite. Fluorite has a distinctive blue -green color and has some lapidary use although it is too soft to be really satisfactory as a gemstone. One of the rarest forms of fluorite is so-called Derbyshire Blue John, a very beautiful yellow and blue banded fluorite found in only in two mines in Derbyshire, England. Hydrofluoric acid is produced by treating fluorite with sulphuric acid (happy fun times.) HF is extremely poisonous and corrosive to living tissue, having the ability to cause deep, initially painless burns and instant damage to the lungs and eyes on contact; by interfering with calcium metabolism it can cause cardiac arrest and death after relatively small exposure. It is one of the two dance partners in everyones favorite uncontrollably hypergolic rocket fuel, chlorine trifluoride (mixing chlorine and fluoride, WHAT COULD POSSIBLY GO WRONG.) This is cool: other light chemical elements, from carbon to silicon, are hundreds to thousands of times more common than fluorine. This is because it can only exist transiently as a product of stellar nucleosynthesis, as under the conditions necessary for its formation, it tends to fuse readily with hydrogen to form oxygen and helium, or helium to form neon and hydrogen; that it exists at all outside of very momentary instances in stellar cores is something of a mystery (says Wikipedia.) One hypothesis is that fluorine is blown out of huge blue giants --Wolf-Rayet stars --by powerful solar winds. Finally one of the best known uses of fluorine is in making PTFE, or tetrafluoroethylene, better known as Teflon. This material was discovered by chemist Joe Plunkett, in 1938; he was venting a steel bottle of tetrafluoroethylene, and found the bottle refused to empty completely. On cutting the bottle open he found the walls coated with a waxy substance which proved to be polymerized tetrafluoroethylene; the chemical had reacted with the iron in the walls of the bottle, under pressure, to form a new material. It begins to emit toxic fluorocarbon gasses above 200C. At 250C it begins to deteriorate significantly and at 260C decomposes. I wouldnt cook with it, although if you have some magnesium and aluminum powder, you can mix them with powdered PTFE to make infrared decoy flares, useful for distracting heat-seeking air-to-air missiles that are nosing up your tailpipe. That is all.
Posted on: Wed, 28 May 2014 02:19:38 +0000