Taa daa! After about 1 1/2 hrs last night, she's done. The outside circle is 7.5 cm in diameter, I've photographed the stone with my chequebook to give a better idea of the size. It was challenging to work with such small lines so close together, but I'm very happy with the results. I think I'll have to go the the beach today for more art supplies. ;)
I'm working on my second stone, and thought I'd post work in progress images to document how I'm doing this.
Following my crude little green numbers, I'll walk you through. #1 is the original line drawing. What you can't see is that the back of the paper is covered in a layer of red pastel dust. Previous to this photo being taken, I taped the pasteled pattern to the stone, and traced the lines. When I lifted the paper, the rock looked as shown at #2. You can (kind of) see the red lines on the stone. Next step is to use a pigment pen to trace the lines on the stone, so then I can wipe off the red dust. #3 are my mask and goggles - sexy I know, but I don't want stone dust in my lungs or contacts. #4 is my trusty dremel tool, along with #5, my diamond bits. And #6 is the toothbrush I use to keep the rock dust/water gunk off the stone so I can see what I'm doing.
And here we are after about an hour of work with the dremel. Getting there, but still at least another hour on this one. This was a challenge, as I didn't know if I could work this small... if your monitor is set like mine (800 x 600), then this photo is about life size. The spiral design is about 8 cm across. 
