In general, all are considerably less hard than diamond. Moissanite in fact has the next refractive index than diamond, and when presented beside an equivalently sized and Slice diamond will show more "hearth". In very uncommon situations tourmaline is found in blue shade, most famed being Paraiba tourmaline and indicolite https://gemstones-prices30739.blogsmine.com/31012658/gemstones-list-options