Mercury - Quicksilver Black Diamond 3-Blade Aluminum Propeller 15" Diameter x 17" Pitch Right-Hand Rotation Three Blades Aluminum Phantom Black Finish QA1912X. Overview. There's a reason the Quicksilver Black Diamond has become a favorite among boaters - it's dependable, smooth, and easy to live with. You can feel its balance the moment the throttle moves forward. The boat glides onto plane, the steering stays light, and everything just feels in sync. This isn't a flashy performance prop - it is