Perched on a white albite matrix are lustrous and translucent, tabular blue crystals of rosterite, to 2.1 cm across. This is a more massive and 3-dimensional specimen than most, with a central, fat crystal that is among the most robust in the pocket at over 1 cm thick. Deep color. Vorobyevite (or Rosterite) is a very rare varietal of cesium rich-beryl, which has caused the crystal structure to deform and have a strange look compared to other aquamarines. This is analogous to the related species Pezzottaite, from Madagascar.