Jim, I'm not at my house until Sunday PM, but I do know I have at least one "block" about 3" x 3" x 2" of a Tasmanian Burl. I don't believe it is Myrtle, possible Tasmanian Oak Burl, or a variety of Eucalyptus. It does have cracks, so I suspect it would make nice blanks if cast in a colored PR/Alumilite. These would be shorter blanks, but at 3" should do fine for 1 or 2 blank kits.
When I get home I'll check and send you a picture for you to consider.
You are a newer member and I'm not sure of your turning experience (Please, no offense intended). I would not suggest these subsequent blanks (possibly 6) as "beginner fare" and really suggest they be cast to fill the voids, or you be mindful or turning blanks with questionable "explosive potential for excitement). I do believe the wood is extremely hard.
I'll remember to do this on Sunday.
This is what a pen would look like from a similar block.