Questions and ideas for a magic item that can change only the actual item's appearance.

In a campaign I'm in, I'm playing a rogue. I have a jade medallion/pendant that is the symbol of my family. My rogue has several holy symbols and family crests stored in his chest. He uses them to help trick people and gain trust or access to areas. I wanted to have a magic item commissioned out of that jade (in the future, as I will need to save gold I'm sure) that can cast shape stone at will, but only upon itself. The jade medallion can change how it's formed to take any shape that I want it to look like at the time.

If this item was in your game, how expensive would this be to commission? How many charges a day would be fair? And how difficult would you think it would be to make it?

I want him to have a single medallion that is any holy symbol he chooses at that moment. It can have only 1 or 2 charges a day, that's fine. It doesn't need to be super OP. Just a really nice utility item that already goes with how my character plays.

I dont want it to be able to affect anything other than the shape of the jade medallion. And I want to be able to do it without the use of words to activate it. Either at will, or reacts to my touch.