1 Hardness: cubic zirconia has a rating of approximately 8 on Mohs hardness scale vs. a rating of 10 for diamond. 2  Specific gravity: the density of cubic zirconia is about 1.7 times that of diamond. 3  Refractive index: cubic zirconia has a refractive index of 2.15â2.18, compared to a diamond's 2.42.he synthesized material is hard, optically flawless and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is a zirconium silicate (ZrSiO 4).
When GPS service was first made available for civilians in 1983, for national security reasons, the U.S. military decided to scramble the signal, making it a little too inaccurate to be reliable. This practice, also known as selective availability, was aimed at preventing military use of GPS by the enemies.
In March 1973, 1974 and 1975, the Selective Service assigned draft priority numbers for all men born in 1954, 1955 and 1956, in case the draft was extended â but it never was. SOURCE: âCHANCE AND CIRCUMSTANCE: THE DRAFT, THE WAR AND THE VIETNAM GENERATIONâ BY LAWRENCE BASKIR AND WILLIAM STRAUSS (1978)