Possible Clues:

• Some gent renovated jewel
• Some gent whacked gets shiner
• Feature of engagement ring some gent waved about
• What could be part of a spray with stem gone bad
• Valuable rock for cutting and polishing
• Precious mineral
• Little Margaret goes up the street with one precious item
• It's multifaceted
• Gnome set out to find precious rock
• Ruby, e.g