Hello,
You could take your jewellery to a jewellers,and have them do this.
But if its alot, that you need to take, then this option wouldn't be very safe.
If you contact a jewellers via telephone they maybe able to advise.
I know Beaverbrooks did a ring for me years back, but after valuing and insuring it for many years, i found out that my contents insurance with Abbey covered it.
The contents insurance usually cover per item upto £1,000 and if the item is valued higher then extra premium is required.
Hope this helps?
A.x