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.
specialized aircraft or military can go much higher and much faster the SR71, a true airplane, flies at 80,000 feet and flies at mach 3.2 which is around 2400 mph over ground depending on winds also the Mig 25 foxbat, also a true airplane, flew once at 125,675 feet for 20 minutes and another time, at mach 3.6.