Guaiacum officinale is the World's densest species! Smelling of vanilla and honey, it is a unique wood that is great for turning projects and is difficult to obtain! It's oily properties have long been taken advantage of for bearings, propeller shafts, and insulators.  When friction (heat) occurs against this wood, the guiac become fluid and acts as a lubricant, actually reducing friction and heat when used in bearings and similar applications; as the temperature decreases the guiac is pulled back into pores.  Lignum Vitae is excellent for use where mechanical lubricant is difficult or impossible to apply.  A suitable substitute is Vera or Argentine Lignum Vitae.  It is the World's second densest wood and is usually half or less expensive.  Guaiacum officinale is protected under Cites and can only be shipped out of the US with special permits.  Central America