how is gaint budda of leshan made?what kind of rock is used?

The giant buddha was carved on the rock of the mountain and the project lasted 90 years by three generations of craftsman. The rock here is red gritstone and softer than granite, so easier to carve. They carved the buddha from the top of the mountain rock to the bottom. There are holes can be still seen now in the cliff beside the buddha's arms, shoulders and belly. There were wooden buildings, meant to cover the buddha.