Betelgeuse, a bright star in the constellation of Orion, is much cooler, about 6,900 degrees F, and so even to the naked eye has an easily identified red hue. The brightest star in the night sky, Sirius (also known as the Dog Star), has a surface temperature of about 18,000 degrees F, which gives it its bluish tinge.
At 1109-carat, the Lesedi La Rona is the largest gem-quality rough diamond to be discovered in over a century and the largest Type IIa rough diamond in existence today. Image: Lucara Diamond Corporation. At 118.78 carats, the âThe Graff Venusâ is the worldâs largest D-color, Type IIA, flawless heart-shaped diamond.
The quality of diamonds can be split broadly into gem, near gem, industrial and boart categories. In rare cases 90% of diamonds in a deposit are of gem quality; but most economic deposits contain 20 to 40% gem quality diamonds.utting and polishing of a rough diamond may start with 'cleaving' (splitting) a diamond along its grain (weaker crystal planes) to divide it into smaller pieces or remove flaws and impurities. Very thin circular metal blades impregnated with diamond dust or lasers are used to saw across the grain of diamond.