Nice, that's shaping up well.
I haven't used the stone one yet since I don't have a car that has the same thread pitch/size for the shifter. I'm also redoing the surface since I didn't like how it turned out and trying to make the metal portion pop more. But yea, I'm quite curious to see how it is. I forget how much it weighs, but it's pretty hefty being granite.
Edit: I forgot to ask, did you predrill the bottom for whatever you're using to thread on to your shift lever?