This is a procedural material working in Cycle the best.

It work in EEVEE but with no displacement.

You can Edit the material in shaders
there is a node for base color its all the correct color hex codes for all stones.

There is also a node called correct IOR with the same stones names just match the 2 in color and ior to get the most realistic version of that type of stone or crystal.

There is a color ramp for the roughness and there is 2 nodes for you to play with the displacement.

You model need to have some divisions to see the effect of bump and displacement.

I personally use it with experimental cycle and i put an adaptive subdivision modifier on my object.