The answer is the spring equinox
In fact, since the Moon is constantly rotating on it's own axis, there is no area of the planetoid which is permanent darkness, and the far side of the Moon is only completely devoid of sunlight during a Full Moon - when the Sun is facing the Moon with the Earth in between.
Answer: Gneiss
Explanation: Gneiss is a metamorphic rock formed from shale at very high temperature and pressure condition. They exhibit a preferred alignment or orientation of platy minerals called foliation. They are coarse grained and exhibit gneissose banding. They are formed from highest grade regional metamorphism with temperature between 450 - 600 degree celcius and pressure between 800 - 1000 mega pascal. They generally occur in cores of fold mountain belts where mountain ranges have been eroded.