Chrysoprase has a Trigonal crystal system and is in the mineral class of oxide, the quartz group. A form of Chalcedony, its apple green coloring is obtained from traces of nickle. The nickle is dissolved from the surrounding rock by silicic acid and will only provide the color as long as there is water present in the crystal lattice.

During its intermediate stage of formation, Prase Opal is created which appears to look almost identical to Chrysoprase. As water is lost, the transformation to Chrysoprase occurs, and as it dries even more it loses its bright green color and slowly pales. You could duplicate the earth’s natural processes by placing an Opal on a bed of salt which would remove the water from the crystal lattice, although I definitely could not recommend that for the Opal. This is one of the reasons I never use salt to clear or cleanse any of my gems and use my herbal mix instead.