Thanks, everyone, I'm glad you liked it. I've had internet problems so haven't been able to respond sooner, I'll try to answer some of the questions.
"X-Blocks" is a technique and ruler system developed by Patricia Pepe of Quilt Queen Designs. She has also written two pattern books and numerous individual patterns. The quilt I've shown here, Thornton, is an individual pattern.
The rulers come in two sizes, 6-1/2" and 7-1/2", and each size also has a companion "Mini" ruler and "BellyButton" ruler. The minis are sized so that four mini blocks equal one of the large blocks. Or you can use the Minis on their own to make a smaller version of any pattern.
The BellyButtons are sized to fit in the middle of the large block. What I mean by that is when starting certain X-Blocks patterns you sew a nine-patch block, then cut it with the large ruler. Instead of starting with nine plain squares, you would first make a pieced block using the BellyButton ruler which will become the center square of the nine-patch. This allows for some completely different looks in the finished quilt.
I have a sample down at my shop that I can take a photo of tomorrow and post to give you a better idea of how the BellyButton works. Until then, I hope everyone is having a Happy Mother's Day!