Silicon Allotrope Synthesized (image) Carnegie Institution for Science Share Print E-Mail Caption View through the channels of Si24. This new zeolite-type allotrope of silicon (isotypic with the zeolite CAS) has an open framework comprised of 5-, 6- and 8-membered sp3-bonded silicon rings. Credit Timothy Strobel Usage Restrictions With credit Share Print E-Mail 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.