The mountain is divided into three formations that are divided by faults, or, detachments, that overlap each other. They are the Qomolangma Formation, the North Col Formation, and the Rongbuk Formation. The Qomolangma Formation is at the summit and consists of limestone, dolomite, and siltstone. The bulk of the mountain is the North Col Formation, and is filled with marble, phyllite, and semischist. The base of Mount Everest is made up of the Rongbuk Formation. It is filled with sillminite-K-feldspar grade schist and gneiss, as well as numerous sills, dikes, and leucogranite.
Sir Edmund Hillary of New Zealand, and Tenzing Norgay of Nepal first successfully climbed Mount Everest in 1953. The mountain has two main climbing routes; you can climb up the northeast from Tibet, or from the southeast ridge in Nepal. There are many other routes that are possible to climb, but these two are the most popular. The southeast out of Nepal is the easiest way to go, and is the most frequently used.
The best time to attempt a climb of Mount Everest is in May, before the summer monsoon season starts. Other times of year, the weather patterns are too unpredictable and make climbing extremely demanding. Many people have died while attempting to reach the top of Mount Everest, the major cause being avalanches.