Cruising thru' Quilter's Cache, I found some similar blocks. One is "Our Country" (http://www.quilterscache.com/O/OurCountryBlock.html)
and the other is "Cross & Crown" (http://www.quilterscache.com/C/CrossandCrownBlock.html).
I thought it might be something like 'Crown of Thorns', but, at least on the Cache, I wasn't even close!
It's a beautiful quilt! Enjoy it :D