NMR-012: 29Si and 11B NMR Spectroscopy and Tube Selection 29Si and 11B NMR Spectroscopy and Tube Selection Pyrex is a Borosilicate glass containing approximately 80% Silicon Dioxide and 12% Boron Oxide. Tags: 29Si, 11B, NMR Spectroscopy, Tube Selection Read more about NMR-012: 29Si and 11B NMR Spectroscopy and Tube Selection