Generally speaking, all are a lot less tough than diamond. Moissanite really has the next refractive index than diamond, and when offered beside an equivalently sized and Reduce diamond will show extra "fireplace". In quite rare situations tourmaline is found in blue coloration, most popular being Paraiba tourmaline and indicolite https://gemstonessouthafrica29629.theisblog.com/30740342/gemstones-found-in-namibia-an-overview