Dark clean

An uncleaned Dark Fossil Rock, as seen in the original Fossil Fighters game.

Dark Fossil Rocks are fossil rocks that contain jewels, red-boned fossils, or coprolites, know as dropping fossils in both games. They are covered with a black outer layer that is impervious to both the Drill and Super Drill, along with the X-Ray. Because of this, it is nearly impossible to know what is in a Dark Fossil Rock until you clean it, with the exception of Dark Fossil Rocks that naturally have exposed sections. Their hard outer layer can make them very difficult to clean as well, especially with certain kinds of fossils with weak bones or overly exposed regions. Dark Fossil Rocks can be sold to the shopkeeper in the Fossil Guild for 400G on their own, though most find it more beneficial to unearth what they have inside and sell the treasures within, for they are often more profitable.

Fossil Fighters: Champions introduced Giant Fossil Rocks and Curious Fossil Rocks. The dark versions of the aforementioned sell for 800G and 600G, respectively.

In addition to the "normal" Jewel Rocks, Dark Fossil Rocks can also contain: