corundum, gems

Corundum. Hot pink” sapphires were available from many dealers. These "pinks” come from Burma, Kenya, Tanzania, and (the largest ones) Sri Lanlta. A few small pieces from the Uinba region of Tanzania were actually red, but they lacked the brownish component typical of rubies from this region. Perhaps heat treatment is being used to drive this component off (for more inforination, see Gem News, Fall 1987). Many star sapphires in a variety of colors were also seen. One stone of special note because of its color, quality, and size was a magnificent 23.97-ct translucent purple Sri Lanltan gem (figure 3).The presence of a fluid inclusioil near the "heart" of this stone proved that the color was natural and not the result of heat treatment. A few translucent to semitranslucent green star sapphires, said to be from East Africa, were also available. The color of the two we observed was a slightly grayish pastel green. These are the first truly green asteriated corundum the editors remember seeing."