Beryl
Gibbs G V, Breck D W, Meagher E P
Lithos 1 (1968) 275-285
Structural refinement of hydrous and anhydrous synthetic beryl,
Al2(Be3Si6)O18 and emerald, Al1.9Cr0.1(Be3Si6)O18
Note: anhydrous emerald
Locality: synthetic
_database_code_amcsd 0019468
9.219 9.219 9.198 90 90 120 P6/mcc
atom     x     y     z occ Biso
Al     2/3   1/3   .25 .95  .43
Cr     2/3   1/3   .25 .05  .43
Be      .5     0   .25      .23
Si   .3875 .1160     0      .11
O1   .3120 .2373     0      .38
O2   .4993 .1456 .1450      .27