Crown Mimic Style Stone
In Update 9 ZOS added a new style material exclusively to the Crown Store called the Crown Mimic Stone. This style material is able to be used to craft any style of item in ESO.
You can use this material at any crafting station to make any style of armor or weapons that your character has learned. You have to have used the Motif of the style you are trying to make first!
Crown Mimic Style Stone
I get the feeling though that you cannot use them at a jewellery crafting station, at least I have not found a way to use them