Gehlenite.
Description from the source:
Gehlenite ( Ca2 Al (Al Si) O7 tet.), Le Selle, Monzoni, Trento, Italy. Small but evident. 1,5x1x1 cm; 3 g with box. Source:Simone Citon Contributor:John Gray Acquired:28 January, 2009 Text Updated:29 January, 2009 Price: Trade Size: 0.6" Composition:Ca2Al(AlSi)O7