I've been viewing YouTube video tutorials on Blender glass, and I have combined some of the ideas and improved them further, to make my own glass material that does optical dispersion. This is how glass splits light into the colours of the spectrum, as the refractive index is different at different wavelengths of light. I would not have got every far without those YouTube videos so I haven't got too carried away with my own genius, but in the end I have managed to make a very convincing glass material that is highly adaptable. It renders more slowly than the standard Blender glass BSDF shader, so that should still be used for items where the dispersion wouldn't make much difference to the appearance, but if glass is front and centre in a render I will certainly find it useful. The object collection on the left uses the standard Blender Glass BSDF shader, the collection on the right uses my new dispersive shader. My shader is not scientifically accurate, but it does look convincing. There are even little rainbow caustics on the surface the objects are standing on, notably by the Stanford Bunny. Rendered at 3840x1600 in Blender 4.1 (in less than five minutes, even though there was lots of other stuff running — I love my ancient Mac Pro).