I think that there is a bit of a mis-understanding about the wood used. IIRC, it was billed as the densest wood that can be worked. In other words, not petrified. I have no opinion on its performance as a footer (in fact I'm not even sure if I am in the isolate or drain camp on vibration).
prehistoric footers
I saw an ad in the tweaks section of audiogon about footers made from wood obtained from preserved prehistoric wood. The ad was from a company in New Zealand. It was interesting in that the wood was mineralized and very dense. It is supposedly used for some kind of instrument making. Unfortunately the ad appeared for only one day. Anyone know the name or website for the company? Thanks.