It is called Swirls and it was a free pattern.
http://www.pbtex.com
The pattern calls for 8 inch square but I just used 5 inch charms instead. I love the pattern and it is so simple, just HST. I used a couple of marble charm packs.
I just went to the website and they no longer have that pattern available. Just make HST that are half light and half dark then put a narrow sashing and borders. The layout is easy to figure out with a picture.