Question- where to get quality diamond bits I’m newer to this and wondering where does everyone get their diamond bits either for Dremel or Micromotors from? And what brands?  

I’ve noticed even the Dremel branded ones seem to wear out quickly and are just coated with diamond dust rather than having diamond dust throughout the bit so it continues working as it wears out.

Is there a specific term for that type of diamond bit? Searching only brings up the cheap coated kind.