I don’t know about the power of this, but a high quality opal has a play of colors & luminescence that is ethereal.

Some meanings-
‘Opal - Divination and prophecy, balances chakras, used for centering self, aids in channeling and teaching truths to others, psychic journeys, anchor of hope, stone of cupid.’
http://www.sedonawolf.com/Stone.htm

Allot of information about the metaphysical properties of opal.
http://shimmerlings.com/gemstones/opal.htm