Allotropes of carbon dispersion of light of diamond make it useful for both industrial applications and jewelry. Diamond is the hardest known natural mineral. This makes it an excellent abrasive and makes it hold polish and luster extremely well. No known naturally occurring substance can cut (or even scratch) a diamond, except another diamond. The market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100
The Hardest Day air or on the ground. If the battle continued at this rate the Luftwaffe would wreck Fighter Command, but it would come close to wrecking itself in the process. Citations The Hardest Day The Hardest Day is a name given to a Second World War air battle fought during the Battle of Britain on 18 August 1940 between the German Luftwaffe and British Royal Air Force (RAF). By June 1940, the Allies had been defeated in Western Europe and Scandinavia. Britain rejected overtures for a negotiated peace. Consequently, Adolf Hitler issued the German armed forces ("Wehrmacht") Directive No. 16 ordering