Well, it's not exactly a new rock, but it's definitely pretty hot. It's a mineral deep inside the earth's mantle and most people may never have heard of it. It's called silicate perovskite and it's chemical formula is (Mg,Fe)SiO3.
Estimates are that its presence is a result of a meteorite that hit the ground in Australia in 1879. It's cube shaped and is a combination of two positively charged elements held together by one negatively charged element. How much of it is there? Some experts put the figure at about 38% of the earth's total volume. It can only exist however, in an environment of extremely high temperatures and pressure. That's why it's so deep under the earth's surface, somewhere between 420 and 1680 miles under our feet. Temps there can reach 5,000 degrees and the pressure is approximately 1.4 million times that of the atmosphere at sea level. Identifying a naturally occurring sample was difficult, but using a sophisticated instruments, it's now been found. It also has a name, bridgmanite. The name is in honor of physicist Percy Bridgman who won the Nobel Prize for Physics in 1946 for his work in high pressure physics and crystallography.