The four C's of diamonds are easy to identify: Carat, Cut, Color, Clarity. The four C's of a brand? Maybe not so much. Here, we ask Pietra's jewelry designers to tell us what makes up their four C's: who is their dream celebrity? What is a common trait of all their amazing clients? What is the most prized piece from their collection, and what is unique about their craft.

One of my favorite things about Marie Mas jewelry is its inherent ability to transform. What may look like a simple ring, with a different touch of light, because an entirely different color and shape, thanks to her highly technical, and yes, patented, ways of designing. Here, she answers our Four C's.

CELEBRITY

I think I'd love Angele. She's a French singer. She's very dynamic and speaks about what's really happening right now. She's really of the time. She's really modern and really surprising – it's always surprising what she does.

CLIENT

I'm always surprised by my client, which is great. Every time I travel I discover another kind of person! It's really nice! But I think, generally, my clients have their own taste. They are not people who follow. They are more people the type of people to want something very special. And I see both women buying for themselves, and men who bring their wives, because the men seem to like the technical part of my pieces.

COLLECTION

I think that my favorite or most meaningful creation from a collection is a ring in the first collection called Dancing Open Ring. It has one diamond on one side in a marquis shape and on the other side you've got six stones that can be either blue or purple. It really is the identity of the brand. It's wearable and at the same time it's "wow!"

CRAFT

The idea behind the brand is "moving jewels." There's always a mechanism in some sense, a surprise. I have patented most of the techniques I have developed. So, that's really what makes the brand unique. You're going to find something that you didn't see anywhere else.