You gotta love artists who create content for VRChat, sometimes their vision is something else. Just take a look at omochi_otoca's latest project for the game: they made a gorgeous shiny volumetric opal material, which is not only worth admiring as a stone but can also be used for an avatar's hair.
Moreover, the Unity-made shader is available as a ring for your VR characters on omochi_otoca's Booth.
There is a whole collection of gems, like the magical jewel eyes the creator showcased this year.