This outstanding example of a Muhuashi (Petrified Wood Scholar's Rock) measures 8 inches by 5 1/2 inches by 4 inches tall (including the carved wooden stand it sits in). One photo enlargement shows the stand and the bottom of the rock.
It has the appearance of a craggy old mountain. It was at one time part of a collection of jade mountains. The mineralized wood is actually as hard or harder than jade.
It is difficult to put an actual age on this stone, but we can easily assume that it's age can be measured in centuries, lot's of them!