That’s where the Black Opal Edition Q50 Red Sport 400 gets its mojo from. The 3.0-liter twin-turbo V6 with 400 horsepower and 350 pound-feet of torque doesn’t hurt, either.

The most valuable black opal features bright red stone against a very black base. In the '80s and '90s, gem-quality brown diamonds were worth about $1,500 per carat, but now many sell for up to ...