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.
As originally deployed for civilian use, the GPS system uses one type of radio signal, called L1 C/A. GPS III will add three new civilian signals to that mix â L2C, L1C, and L5 â while keeping the L1 C/A signal operational for a total of four civilian signals. L2C. From the perspective of everyday GPS users, the most important may be a second civilian GPS signal, dubbed L2C. The L2C signal is a bit clearer and easier to receive than the legacy L1 C/A signal used by most GPS receivers today.