This all makes me wonder if diamonds only exist on accident , like perhaps white diamond was the original (I picture the gems origin something like transformers or something , it doesn't really matter where they came from though) and perhaps after a few millenia , Yellow diamond came to be or was even created by white diamond to watch over a new corner of the galaxy. Then Yellow created Blue diamond after many thousands of years and Blue Diamond much more recently (in gem time) created Pink Diamond to farm out the outer arms of the galaxy. Pink Diamond went to work , using earth and it's moon for her first attempt at building her own servants (of all types) and eventually generated Rose Quartz (perhaps rose is the only such quartz of all the gems, something that earth was uniquely able to create) but maybe earth made gems are also more prone to free will ? like all the crystal gems were slightly defective but perhaps they don't feel that's ok until they get to earth ? I'm starting to ramble here but maybe Pink Diamond wasn't a bad guy , perhaps she was made an example of and Rose was coerced into doing the deed or something ? either way whatever happens in SU , I'm looking foward to future seasons explaining everything.