The category with the highest number of workers in 2011 comprised the 21.4 million office and administrative support occupations, which had average earnings of $2,843 per month, $34,120 per year or $16.40 per hour.n 2011, food preparation and serving related occupations were the lowest-earning category, earning an average monthly $1,785, which equaled $21,430 per year, or $10.30 per hour.
Blue diamonds are extremely rare. They generally have a slight hint of gray, so theyâre rarely as highly saturated as blue sapphires. Their color is caused by the presence of boron impuritiesâthe more boron, the deeper the blue. Fancy green diamonds are typically light in tone and low in saturation.
Gray & Blue Diamonds. For the most part, blue diamonds get their color from boron. When this impurity is present, it bonds to carbon in the crystal structure, absorbing red, yellow and green areas of the color spectrum. It's not until the last leg of their journey to the earth's surface that diamonds get their green color. Just as they are about to leave the uppermost layer of the crust, these stones absorbs naturally occurring radiation, which causes them to reflect a green hue by absorbing red and yellow light.