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.
The Selective Training and Service Act of 1940, also known as the Burke-Wadsworth Act, Pub.L. 76â783, 54 Stat. 885, enacted September 16, 1940, was the first peacetime conscription in United States history. This Selective Service Act required that men between the ages of 21 and 35 register with local draft boards.Later, when the U.S. entered World War II, all men aged 18 to 45 were made subject to military service, and all men aged 18 to 65 were required to register.nder the Selective Training and Service Act, all American males between twenty-one and thirty-six years of age registered for the draft. The government selected men through a lottery system. If drafted, a man served for twelve months.