If you have less than stellar credit, can you buy a wedding ring with a down payment?

I would like to purchase a wedding ring, but my credit is still being restored to a good standing. My score will be much better by December, but even with my credit looking less than fair, I would like to purchase the ring by September. If I go into a jewelry store with half of the price of the ring in cash on me, will they allow me to pay a down payment and pay the rest off in installments?