I know it's hard to believe, but this piece is carved from a massive, almost 4" hollow blank marble which Doug Whalen created for Nathan. Nathan and Doug did this piece as a demo for the Flow Magazine, and I can have Nathan send you a copy of that Flow issue signed by both of them if you would like. My favorite thing I discovered about this piece is that you can put a light inside and see it light up brilliantly and beautifully in the dark! My favorite application is to place one of those flickering candle style lights inside, so the light gently flickers as you stare at the glass. Soooooo COOOOOOL!!! It will come with a small LED light. Signed with carved 'NG' insignia.