Rose de France has a hardness of 7.0. This pale lilac transparent gem is found worldwide and is a type of quartz . This cut has little wastage of stone, but is not nearly as reflective as the brilliant cut , which was invented later. Rubellite is red in both incandescent and daylight, and is more valuable than other varieties of red tourmaline. Rubellite is sometimes treated with fillers to increase the clarity of the stone.
Rubies range in color from the classic deep red to pink to purple to brown.
During the renaissance, people thought that rubies could counteract poison. The biggest ruby in the word is the Raviratna, which weighs 3,600 carats. Rubies have a hardness of 9 and a specific gravity of 3.9 - 4.1. A Russian gold finish is a matte, antique-look finish. This beautiful stone is usually cut as a cabochon .