Cuff with black carbon finish over copper

http://www.ganoksin.com/gnkurl/ep801f

What is this black carbon finish? how is it done, and can it be
donein a small shop?I have no interest in the design, but would like
to knowhow to achieve this finish on silver, copper and
bronze. Thanks, Andy

What is this black carbon finish? how is it done, and can it be
donein a small shop?I have no interest in the design, but would
like to knowhow to achieve this finish on silver, copper and bronze.
Thanks, Andy 

I do not know for sure but it looks like a black (DLC) diamond like
coating. It is carbon applied in a vacuum vapor deposition system to
achieve a very specific crystal structure. The coatings share some
of diamonds properties so they are used to increase wear resistance
and improve other properties on industrial parts. When deposited
with some graphite in the mix it is a nice shiny black. It is being
used in a lot of jewelry and watch designs. This is not a studio
level process. If you do a bit of Google searching you will find
companies who do this.

James Binnion
James Binnion Metal Arts