Rainbow moonstone, as the name suggests, connects with the Full Moon but is also a crystal of the Goddess and Divine Feminine. This makes it an excellent crystal if you are looking to connect in with a specific Goddess and helps messages to come through and be interpreted during journey space. Personally, I like to charge rainbow moonstone under the Full Moon, then use that crystal for any spiritual work for the following month to connect in to the Moon energy and the Divine Feminine within.
Rainbow moonstone is excellent if you suffer from any hormonal issues, although the energy can sometimes be a bit overwhelming. However, with the addition of black tourmaline in this palmstone this will help to ground and stabilize the energy giving it a much better balance allowing you to work with the moonstone and the Goddess from a grounded space.