I made this one years ago for my girlfriend. I started with a small block of resin which I cast specially, then used a razor saw, needle files and wet & dry paper to carve it. I found the colour of the raw resin to be a pretty good match. It took a while but was a lot of fun.
Funnily enough the hardest part was finding the leather. I finished up going to Covent Garden, buying a bead necklace and throwing away the beads!
It may not be perfect but I'm proud to say she's worn it ever since. Oh, and she's now my wife. :$