White Fire (1984) Robert Ginty, Fred Williamson (Action, nudity, shootouts)

When Bo was a child, a mysterious stranger murdered his parents. Only Bo and his sister, Ingrid survived the bloodshed. Now, twenty years later... Bo and his sister are grown up. They are now employees at a diamond mine-shaft located in the desert. As mischievous as they are, they stumble upon the discovery of a legendary diamond, the “White Fire.“ However, this rapture for the diamond has provoked the angst of some short-tempered, not-so-nice villains. The quest to capture the most sought-out diamond in the world is afoot..