Designs have a way of reappearing in our repertoire. We used to make a silver piece called the "Mothership". It has a domed washer, with a concave interior. When polished, you could see yourself upside down and right side up at the same time.
In translating that form into gold we did it like this. Make a sweet 18 karat yellow lentil shape- keep the back a nice dome, and on the front, bezel set a large ruby. This stone is about 7mm so it is definitely huge! Surrounding the center stone, we flush-mounted rubies and diamonds in all of the spots that a UFO would have their running lights. (This is theoretical- haven't seen this sight, only have read about it). Looks good on a chain, looks GREAT on a neck-wire.
Depending on type of ruby (fissure-filled/ natural/ lab-created are all options) this piece can range in price from 2,000 to 16,000. The top end of that scale would be for a super clean natural ruby or other fine gem. This pendant also looks great in white metal with all diamonds...