Diamond professionals use the grading system developed by GIA in the 1950s, which established the use of four important factors to describe and classify diamonds: Clarity, Color, Cut, and Carat Weight. These are known as the Four C s. When used together, they describe the quality of a finished diamond.
0. Most Americans adjust their clocks for Daylight Saving Time (DST) once in the spring and once in the fall -- but residents of two states, Hawaii and Arizona, have chosen not to observe it. This clocks stands in a city park in Glendale, Arizona. Wikimedia Commons. Arizona participated for one summer.
They have never observed daylight  savings since.    During daylight saving time (spring through fall), Arizona is on  Pacific time. All other months of the year they observe Mountain  time. The only exception in Arizona is the Navajo Nation, in  northeastern Arizona, which does observe Daylight Saving Time.    Hawaii  Hawaii is closer to the equator and experiences much less variance  in daylight than the rest of the country and therefore opts out of  observing Daylight Saving Time.