Even standing dead, the wood could be green.  If it is indeed dry, without splits, you've truely got something there.  I had some that split so badly before I got to it that I nearly didn't get to do anything with it.  And, I mean anything.  Think I got a few pens out of it. 

As I remember, it turned nicely though.   8)

Sounds like that's what's been said on two boards now.  Simply, go for it, dude.   8)

I have turned pistachio from several different lots out of California orchards. It was a delight! Cut like buttah, beautiful grain. I've also turned both seasoned and green wood, and both are a delight. The green wood will give you purple-to-black hands, much like walnut. If your supply does turn out to be greener than you think, the wood does like to move while it's drying (particularly if your wood is from irrigated trees with large growth rings), so if you turn to a roughed-out stage leave yourself enough wood to correct the warping after the pieces have dried.

One last thing. Rather than loose pieces with cracks, I've instead filled the cracks with turquoise. This is a spectacular combination!

I turned some Ornamental Pistachio some months ago and it was a nice lime green which turned to a bronze color as it dried.  Very hard wood but turned out very nice.