I don't know of any, but have you searched GIA (gem institute of america), lapidary journal, or Gem & Lap. Wholesalers for blogs?

i came across this one tinyurl.com/6bqmub while looking for a specific charm some time ago

thanks Teeg and keliwhidden; one of our staff is speaking at national jewelry conf on Web stuff, web 2.0.

I appreciate the help.