They may not be Birthstone Mermaids, but they are considered their sisters. So I guess they could be called Gemstone Mermaids. Either way, they will still charm you.

Sunstone and Moonstone are twins, and the only mermaids known to be immortal. Their life force is drawn from the celestial body they are named after. It's a good thing they are immortal, because if either of them died, we would die as well. They are never seen apart.

Sunstone is capable of shooting fire when underwater. The flames are actually solar flares, which can burn in airless environments. Moonstone can create ice crystals. Melting this ice does not easily affect water levels. When they combine their powers, they can control water to do whatever they desire.

Sunstone and Moonstone property of DoctorEvil06