We have just started cutting the first of the ruby rough from Madagascar. This is 100% natural ruby with no treatment from a very, very old deposit. Cutters at the factory are complaining about how hard it is, and this is from people used to cutting ruby and sapphire. We are using about 50% more diamond abrasive as well. I am not sure what that means on the Mohs scale, but it certainly seems harder than normal corundum.
We are seeing to consistent colours so far – a lovely rose colour and a deep, rich plum, both with excellent saturation. The colour and saturation is consistent and make for very good matching in jewelry sets.
All of the rough we have cut has produced cabochons. The stone sliced so far is too opaque for faceting.