Attempt to a standard clean ruby, not to creamy, not to red, not to pink.
Results were pretty good since pure red can be seen mostly on edges and purple-pinks in thinner areas.
If you are interested, you can check this one done by spectral measured values: https://indigorenderer.com/materials/materials/1511
With the same source website you can have plenty differents gems spectral colors
This is just an indigo base diffuse material without any changes, not a ruby material