hi,
I think I have some insight that might help. I am a tee designer but spend about 50% of my day (at my 9-5 job) designing stone and stud layouts for some high end retailers. I mostly design my layouts in Illustrator and create circles in millimeter's since studs/stones are manufactured in mm's rather than inches. I also have some artwork that looks just like a diamond. If you are interested, i would be more than happy to send you a few files.
Email me at
![[email address]](http://www.t-shirtforums.com/?emailimage=22bec2295305b0de4fe079b93bf9b304)
if you are interested.
I hope this helps answer your question.
Thanks,
jillian