An old friend of mine has been making accessories with UV resin.
UV resin is a special resin solution that hardens under UV light.
After pouring the UV resin solution into a mold of your choice, you can put your favorite small objects in the mold, or you can color the UV resin solution itself and then expose it to UV light to harden it into your original accessory.
Even though it is just a resin solution, if you look into it, you will find that different manufacturers have different technologies, such as ease of hardening, blending with inclusions, durability, etc. that Patents for manufacturing methods have been applied.
There are many kits available at general stores and stationery stores in town, and you may see them, but I feel that it is a very deep world where the sense of the creator is important because it is easy to make. (Swimmer)