Do you know a great salesperson that knows next to nothing about jewelry?
Even they don't know how to sell jewelry per se, chances are they could outsell a gemologist or bench jeweler turned salesperson. Those professionals have plenty of knowledge, but it doesn't matter if they don't have a personality to match.
The ideal salesperson for a jewelry business needs to have more than just charm and intelligence, though — they also need to be able to sell with security.