Yes, if the lender accepts jewelry as collateral then it works as a collateral, but I'm pretty sure that only local sellers may accept jewelry as collateral for loans because other lenders who are far away from the borrower may not accept jewelry as valid collateral because it's not possible to send or receive jewelry without heavy taxation. However, if the borrower can pay those taxes then some kind lenders may accept jewelry as collateral it it's value is above the value of loan.