From The Manufacturer/Wikipedia/People Smarter Than Us:
This 1911 is a custom piece featuring the new Black Rock Series finish. Taylor’s is introducing a carbo-nitride hardening process that resists abrasion and keeps the pistol looking new even after shooting thousands of rounds. The Black Rock Series 1911 pistol maintains all the standard features of the classic series Tactical 1911 FS model (#51465). The Black Rock Series finish is also available on the Runnin’ Iron revolvers, and more models will follow.