Semi precious gemstones Photo by Mauro Cateb All gemstones are minerals, but not all minerals are gemstones, so the limited knowledge imparted here can be used on both gemstones and minerals. If you can’t tell what kind of gems you own don’t feel bad because there have been plenty of emperors and kings that didn’t have a clue about what kind of stones they had in their own crown. A good example of this is the Black Prince’s Ruby that resided in the Crown of England for hundreds of years...