Wire Wrap Jewelry and Tutorials by WireBliss. I'm not familiar with this group but the style reminds me of a Lias Barth design who has a great book out, "Timeless Wire Weaving" if you want to give it a try yourself.
This is a sterling silver wire-wrapped Petoskey Stone pendant. The Petoskey Stone is one that I dug up myself at Lake Michigan and has been entirely hand-polished. The pendant measures at about 1 inch long.