False, igneous rocks may classified by chemical composition but may not be crystallized together in the same rock. SO there are always different minerals in igneous rocks.
The astrolabe is an inclinometer, that is considered to ba analog calculator that is capable of solving the several different types of the astronomy and is mostly used measuring the altitude and the navigational aspects of the celestial bodies day and night and it was used in the Islamic golden age and the middle ages. It is also helpful in determining the land and the sea latitude.