"The second type is called Vibranium. This material is mainly used to make Third Generation Machines and Fourth Generation Machines; however, its output is extremely scarce. Those companies that specialize in mining often dig through an entire Mining Star and still produce very little. The third type is called Titanium Stone, which is mainly used for Fourth and Fifth Generations. Titanium Stone is even rarer, and the Old Galaxy has basically been mined empty. Now, only the Three Forbidden Zones still have deposits. As for how dangerous the Three Forbidden Zones are, you should be very clear! Moreover, even within the Forbidden Zones, it's uncertain how much can be mined."
"And what about the last type?"
