Board Thread:General Discussion/@comment-26812261-20150427022224

Basically, assuming that the insignia in Peridot's ship depicting a yellow, blue, and white triangle does, actually imply that there's a White Diamond and Blue Diamond in addition to the confirmed Yellow Diamond, I think White and Blue were both taken out on Earth during the rebellion, and that Blue Diamond might have been on Rose's side. Part of the picture below is from the temple in Serious Steven, wherein we see a mural depicting a white gem on one side, and a yellow gem on the other, both with identical shapes on their chest.

We just so happen to see a similarly-shaped large white gem powering the whole thing. Conversely, we see a similarly-sized blue gem operating the lighthouse in Horror Club, which seems to have a fixation not only on Lars carving his name on one of its walls, but also on the falling out Lars and Ronaldo had (otherwise why bother recording and playing back that part as well). And, just a side-note, the Moon Goddess Statue happens to depict a woman in a similar pose to the two carvings on the ceiling of the temple, with the hands placed on either side of a gem at chest level, and the gem the statue is holding is pretty much identical in shape and pattern to the one they found in the lighthouse. And while the statue references the moon, the yellow gem depicted in the temple carving happens to be portrayed in the middle of the sun.

So my theory is that Blue Diamond, if any such being exists, was in the lighthouse, and the Moon Goddess Statue is modeled after her. It's also probably not true, but why not speculate.

 