The start of all jewellery is in a humble stone. That is where diamonds, gold, gems, etc come from. So does concrete. I don't distinguish between the elements when it comes to value in money. In my hands a piece of concrete and a diamond are equal.
The criterion in which elements works together as a piece of jewellery takes shape. I never start out with a sketch and design in place but rather just start with what there is to work with, a vague idea that starts growing and let the piece dicate what it wants to become. In this case, I have a bit of concrete and a diamond. I know I want to "grow" a ring with concrete and a diamond. That is for me the start of a wonderous new world.