Ackermand et al.(2006): Lazulite-bearing metaquartzite of the Itremo Group (Central Madagascar); Scientific significance and economic importance in Proceedings of the Malagasy-German Research Cooperation in Life and Earth sciences, 5-18
The fastest fighter aircraft is the MiG 25, with speeds topping at Mach 3.2 (2,450 mph/4,000 km/h). Pilots were not allowed to go beyond Mach 2.8. Above Mach 2.8, the engines would overheat and burn up.
If the type of engine is not limited to jet-powered engines, then the North American X-15 is the fastest airplane. Powered by a rocket engine, the X-15 is said to have reached a speed of 4,520 miles (7,274 km) per hour. Like the X-43, it is launched mid-air from a B-52.