Mother-of-pearl, or nacre, is commonly used in jewellery and for decoration, but its incredible strength and low density could be exploited in engineering applications if researchers could find a way to simulate it experimentally. Nacre lines the shells of sea creatures, such as oysters and abalones, is 3000 times stronger than the aragonite form of calcium carbonate from which it forms. Drive a truck over an abalone shell and the shell will be shattered but the nacre remain intact. Now, Pupa Gilbert of the University of Wisconsin-Madison, and her colleagues have used synchrotron radiation to reveal that nacre's secret could lie in the non-uniformity of its crystal structure. "If you understand how it forms, you could think of reproducing it, producing a synthetic material that's inspired by nature," Gilbert says.