Hello there. I saw the pattern in a fabric ad. It is in
Love of Quilting (Fons&Porter), Nov./Dec. 2012 issue, pg 37. Name of pattern is: "Mykonos Marble."
www.patchworkstudio.com. It is an ad for Northcott fabrics, and the fabric line was Stonehenge/Aphrodite. Designer, Deborah Edwards, Northcott Studio. I just studied the photo and graphed it out by hand. It was fairly easy to figure out. Glad you like the quilt! and thanks for the comment! Happy stitching.
Karen