Crystal twinning model (IMAGE) New York University Caption A 3D scan and digital model of crystal "twinning" reveals a shared plane of the adjoining crystals, which gives rise to their shape. Credit Shihao Zang, NYU Usage Restrictions use with credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.