Wow, i am with faldage on this.. i never let a cadger make me feel guilty any more..
"Yes, you are so right-- but i never lend my good jewelry" --or "Yes, but they make such nice costume jewelry these days.. i am sure you can find something wonderful."
if if they are particularly annoying, say "Yes." and nothing else, don't offer the loan, don't take a step to getting it. just agree, your sapphire is a perfect match for their blue suit. and then wait for them to ask you "May I borrow it?" (sometimes they just don't have the nerve!) If they do..
and if they have "borrowed" things before, and not returned them, or returned them damaged.. point it out! "like how you borrowed my silk scarf? and lost it? or how you borrowed my car, and it came back dented? No, i don't want this lost or broken, i am sure you understand." if they just constantly borrow things, just say "No, i don't feel comfortable lending it" if pressed, just repeat, (why? don't you trust me... "i don't feel comfortable lending it"--Do you think i borrow to many things?" "i don't feel comfortable lending it"-- a broken record response.. no anger.. just monotony!)
If they accuse you of being rude, just pause for a moment, and quitely ask, with an incredulous voice, "you think i am being rude? How?" reality is, they are rude. its not rude to say a polite no.
once they realize you can't be manipulated... problem is over...
