Lowest price:$3,226.50Description: 21.51ct 17.69x15.15mm cushion rubellite tourmaline. the name tourmaline comes from sinhalese word turmali meaning mixed . the gem probably got this name because of the variety of colors it comes in and the fact that tourmaline can also be bi- or tri-colored. it ranks 7-7.5 on the mohs' scale of hardness so it is relatively tough. tourmaline is the national gem of the usa but it's found all over the world and colors can vary depending on location.