Petrified wood, in our opinion, is one of the most interesting and aesthetic materials in the world. The ancient wood has been preserved for millions of years by layers of lava, volcanic ash and sedimentary rocks. Special conditions are required to mineralize a tree, which will eventually become a stone, while still retaining the pattern of annual tree rings and fibers. It is truly an anomaly of nature.
The archaeological layers in which the fossilized trees are found vary depending on geographic location and are in the range of 15-240 million years old.
On the hardness scale, petrified wood is a number 7 out of 10, positioned between granite and precious. It is a very hard material, machinable only with diamond coated tools.