Sorry.
Looks a little bit like the one on the left up.
For the
Amethyst
It's a fecetted stone,but you can choose a cabochon too.
I have one here,but a french,from Auvergne.
I have many other stones,waiting for a special use...
I would mount it on a obi saber,but seems it's really hard to find...
I think you have to find the valve adapter,then measure,and finally find a 7,8,9 or bigger amethyst crystal.
Here is just the best for me,accurate,really good quality built,and...electronic inside^^