hey vee.. i thought mineral glass arent as prone to breaking as sapphire? :S.. but as to the water drop test.. from wat i can see that the glass is domed? if this is the case sometimes the water drop test dont work as in the case with my 3717 pilot.. it goes to the side when u drop it.. one other way to tell whether its a sapphire or a mineral is to see the clarity? coz with sapphire u can tell its like a real crystal glass (more shiny and clear, other word the glass itself looks very expensive) as for minerals it feels like plastic (u can see greeny tint on it and its not like an expensive watch).. so yeh im not really sure.. but anyway tap it with ur fingernails and hear the sound