Direct observation of the metamorphism of silicon oxide grains K. Kamitsuji, S. Ueno, H. Suzuki, Y. Kimura, T. Sato, T. Tanigaki, O. Kido, M. Kurumada and C. Kaito A&A, 422 3 (2004) 975-979 Published online: 16 July 2004 DOI: 10.1051/0004-6361:20034353