Reportedly Austraila's hardest timber. While visiting David Linton Furniture store in Malney I purchased a small piece of Ring Gidgee tree. The tree was reportedly harvested from near Rockhampton in Queensland. Based on the Janka hardest test which is a measure of the force it takes to embed a small steel ball into the timber which is then reported as measured in kilonewtons (One kilonewton, 1 kN, is about 100 kg of load under Earth gravity).  It is hard timber, that is for sure, I made 8 timber vibes and broke 3 metal drills making the holes for the hook hangars.