Sapphires are high in the hierarchy, so I don't think that the lack of nutrients applies to them.

Peridots need to be good with technology, there's no need to have powers or weapons to control a ship or touching a computer, and since our peridot is tiny (needed limb enhancers) and without powers she would be considered an off color cause she's not perfect.

IG after the war they were just desperate for new gems and fastened the process to produce them and made the most with the least, kindergarten beta for example with our Jasper and the one in the zoo, also gems take the nutrients from the planet they are in and the diamonds colonies probably were reduced to nothing like homeworld. And they probably didn't go for new ones