Is it ok to mix the energies of the Gem Stone Essences in a healing session?
Yes, that is perfectly fine! In fact a very effective hands on healing session could consist of stone Essences for the 7 chakras. Example you could start by using Jasper Essence on the Root chakra. Then you could proceed with Carneol Essence on the Hara Chakra. Then Citrine Essence on Solar Plexus, Rose Quartz On heart chakra, Sodalite on Throat, Amethyst on third eye and then Clear Quartz on the Crown Chakra.