A Dictionary of Epithets and Terms of Address
This would normally be an endearment, on a par with ‘my precious’.
In Settlement with Shanghai Smith, a short story by Morley Roberts, one man says to another “We wouldn’t part with you, my jewel, not for a thousand’, but this is actually a concealed threat. In Shakespeare’s Merry Wives of Windsor (3:iii), Falstaff woos Mistress Ford with. ‘Have I caught thee, my heavenly jewel?’
This is the complete article, containing 67 words
(approx. 1 page at 300 words per page).