Hello Community I have been using a piece of blue kyanite for 4 years now, almost daily. During this time a 'shell' seemed to have form over the beautiful crystal. I have attached photos. I can see the original crystal colour peaking through on one end and a few flecks around. I have used it quite frequently in bath water (soaps, oils, salt exposure). Not sure if that is the cause. Looking for some insight if possible as my research thus far hasn't been productive. Thank you and much love and light to you all.