Hi rickstd!

Thank you so much for your question

The wood used is called Ipe. Here is a little info about it: Ipe -- pronounced ee-pay -- wood, also known as Brazilian walnut is an extremely dense hardwood, it's resistant to decay, rot and infestation, and has the same resistance to heat and fire as concrete and steel. Ipe wood can be a little difficult to work with, however, and can routinely damage and wear out many tools.

Read more :http://www.ehow.com/about_6503068_ipe-wood_.html