I made this using a cheap 3d pen that I bought from China, shortly after making it the pen stopped working.
I have a background in jewelry making, I have the tools so making a ring as an experiment was pretty straightforward.
I took out a marble from a Ramune bottle and it's supposed to be the gem.
I didn't spend much time worrying about quality since it was just a way to test the pen capabilities.
I wanted to make more stuff with the pen but it stopped working shortly afterwards, and I won't buy another cheap 3d pen.