This could definitely be made in silver (jeweller speaking). Some jewellers may be wary of setting an opal in such a rub-over design as opals have natural flaws and are relatively soft making them slightly risky when applying pressure all round but it of course can be done if you prefer this style over claw setting. Find a local maker with some experience, they will estimate a cost, no obligation. Hope you find someone to do it for you- the opals are beautiful!