As far as I know, a regular Rainbo with the same colors would be a Sunset. In other words, Sunset describes a color combo - red/orange and white ribbons, usually on a bubbly base. I think some may have yellow bleeds too.
It appears to be a stone Agate marble. If you put a light on it and move the marble around in your fingers the light reflection on the surface should jump around if it is hand faceted. If you have a hard time seeing it, do the same with a glass marble for comparison.