There is a Plating solution known as “Black Rhodium” which is used to
give this surface finish. It works exactly the same as “White” Rhodium
Plating—BUT—it is nowhere as durable or as long lasting, so only
use on pave’ or protected area’s. It is not Black black but more of a
"gun metal" Bluing. I use it quite regularly and have had no problems
with it. It is manufactured by Hereaus (Spelling) in Germany.
Sabushka Design Studio
In sunny and hot, hot, hot Johannesburg, South Africa