There are a couple of things that you can use with gemstones that are set.
If its high enough in a rub-over setting / bezel set you can use a refractometer.
Its always easier if the stone is not in a closed backed setting.
You can use a spectroscope, dichroscope, microscope and the UV light. to a lesser extent you can use the the polariscope, but thats all you might have at your disposal anyway.