The East cost Lab had the opportunity to examine an unusually large cat’s eye aquamarine. The oval cabochon 201.18 cts stone, which measured 37.31 x 30.38 x 22.55 mm displayed a fairly sharp straight eye. Two different  types of inclusions cause the phenomenon in this notable gem:
regularly spaced growth zones delineated by planes of reflective flat crystals and films, and perpendicular to these very fine reflective needles.

From Gems & Gemology Fall 2007