Faces

The Sacred Kailash as par Vishnu Purana states that it has four faces and are made of

1. Crystal,
2. Ruby,
3. Gold,and 
4. Lapis.

It is a pillar of the world and is located at the heart of six mountain ranges symbolizing a Lotus.

Source
http://laxmivishnu.blogspot.com/search/label/VishnuPurana