Subject: Re: Superwood
So it is manufactured lignum vitae.

From wikipedia:
Lignum vitae is hard and durable, and is also the densest wood traded (average dried density: ~79 lb/ft3 or ~1,260 kg/m3);[4] it will easily sink in water. On the Janka scale of hardness, which measures hardness of woods, lignum vitae ranks highest of the trade woods, with a Janka hardness of 4,390 lbf (compared with Olneya at 3,260 lbf,[5] African blackwood at 2,940 lbf, hickory at 1,820 lbf, red oak at 1,290 lbf, yellow pine at 690 lbf, and balsa at 100 lbf). The densest of all woods is Allocasuarina luehmannii.[6] Krugiodendron typically has a higher density, among many other woods that vary by sample.