Let me see if I can answer these in the order they were asked.
I didn't have any problem with them breaking throught the resin. I used a digital caliper and took some measurements before I cast them so I knew how much room I had to play with. The Jr. Gent will be a little more exciting since there is less room to play with. It may wind up a bit plump in the middle.
Check out
www.alumilite.com for resin. I suggest you check out the casting forum for more info first.
I lucked into this customer. Actually, he's a high school classmate I reconnected with on FaceBook. He bought one of my peanut shell castings and asked what else I could cast and he suggested the gems.
Actually, we've discussed the possibility of diamonds if he really likes these.
No chasing emeralds around the shop. It was the dining room where I glued it up and yes, I chased them around the table some. I used some plain white paper under everything so I could see them better. They're actually pretty tiny.