Habit modifications of Beryl grown by the flux method

Single crystals of beryl grown by slow cooling from an impurity doped flux without a seed crystal have been grown and their habit modifications studied by SEM and optical microscopic observation. Transition metal doping using Fe 2 O 3 , Cr 2 O 3 , Mn 2 O 3 and alkali metal doping experiments were also carried out. Two characteristics, (1) the ratio (H/W), height to width of the crystals and (2) combination and relative development of crystal faces, were used as a measure of habit modifications. In general, as impurity doping increased, the crystals became slender and the second order prism disappeared. The ratio H/W was less in the larger crystals. This tendency can be attributed to the selective incorporation of impurity atoms on certain faces.