You can buy dremel bits at just about any of the big box hardware stores. I don't know what they cost up in the Northlands but here because they are imported this little bit was the equivalent of $12.00 US !!!!!
I did a bit of surfing and found Harbor Tools had diamond bits of all kinds and sizes for much more economical prices. So the last time El and Jackie went north I asked El a fellow power tool junkie to pick up this set for me. This set goes from 1/16th and has a number of different type heads. They are all diamond coated and cost just under $5.00 for the set!! That made me a happy girl!! :) Now I can't tell you if they will last any longer then their expensive cousins. I'll have to get back to you on that. I do know that everything I've read says that by keeping it, and the glass wet and from over heating the diamond coating last longer.
Okay kids now that you know how easy it is give it a try. I suppose if unlike me your supply of mermaid tears is small you probably don't want to be working out the bugs on them. Maybe you can practice a bit on an old chipped plate or cup, before taking after your precious MMtears!! :)