Is there a way to make volume visible through a glass object in eevee?
Sure. Just use this node arrangement for your glass. Pay attention to the blend modes highlighted on the right:
EDIT - My bad, I didn't see you wanted a refraction component. Adding it is easy, just add a Refraction BSDF and use another Mix Shader to combine it with the existing glass shader. See below (Note - I used a sphere in the image because the gem doesn't refract so well - surprisingly).