Found these samples of petrified wood in the Bowen Basin a few years ago. Quite a bit out there if you are in the right area. Only kept a couple for our collection.
Please excuse my ignorance....is petrified wood a a lot heavier once petrified.
I have something and I thought it was rock and it looks similar to your piece near the VB tinny above.
Yes I would believe that it would be heavier now in the rock state rather than when it was just wood. From wikipedia: "All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue." This would make the wood heavier now.