Board Thread:General Discussion/@comment-26496561-20150426011153/@comment-24986099-20150426015415

If Garnet is a Crystal Gem, that means Ruby and Sapphire are. Garnet is aware that she is a fusion and if one of them didn't consider themself a Crystal Gem, the fusion would be broken due to a disagreement. If they both aren't Crystal Gems, Garnet wouldn't be associating herself with them.

Ruby and Sapphire most likely don't have stars on their outfits because they never plan on defusing, thus not needing to wear the Crystal Gem insignia on their outfits.