I saw that same episode & loved the jewelry. I have used resin, but only for decoupage type stuff....if you pour it over a flat surface, it dries to a glass-like sheen, & is rock hard. Anything you've pasted beneath looks awesome & is preserved. Great way to fix up old tables (I also made coasters, trays etc.).
I am going to attempt the jewelry-I have never added colors, and am not sure about forming shapes-you can pour and have a flat disc form, but I wonder if she has molds. I'm going to check the show site for any instructions.
As for hardening ... contrary to how it seemed on tv, it takes a long time for the resin to harden-24 -48 hours isn't unusual, depending on type used & humidity.
Just be careful-it's basically formed by the reaction caused by mixing 2 different liquids, & of course you have to mix it yourself (otherwise it'd already be hard!). It stinks, is harmful to your skin, and definitely requires gloves & ventilation. That said, it looks incredible when set (& the smell disappears).
I'll let you know if I figure anything out. I bought mine at H. Depot, in the paint/finishes aisle. It was about $16.