The eyes of the great demon Vala were colored and shaped like the blossom petals of the blue lily flower. His eyes transformed into the seeds of blue sapphire gems and fell down on the sacred land of Sinhala (Sri Lanka) and the surrounding tropical areas of Southeast Asia. These sapphire seeds fell in such abundance that these lush and beautiful lands glowed with dazzling splendor.
The finest color of blue sapphire is compared to the blue mountain flowers which grow wild in Sri Lanka. These flowers are so sweet that they attract hoards of bumblebees and parrots eager to drink their nectar. blue sapphires of fine, evenly distributed color, free from flaws and cut to proper proportions for brilliancy are the most valuable.
When blue sapphires have a green or violet tint, are slightly grayish or darkish-blue, or are colored light-blue like the sky, they are of medium value.
Blue sapphires that are excessively dark, light, or uneven in color, possessing a pronounced grayish tone, internal inclusions, external blemishes, visible black spots or internal feathers, are of low quality. Sapphires lacking brilliance due to poor proportions are also less valuable.
Both ruby and blue sapphire are of the same mineral species, corundum, with only the coloring agent differing. Therefore the same methods of identification established for ruby also apply to blue sapphire.
Blue sapphires and other gems should never be subjected to burning for improving their color and clarity, as misfortune will certainly befall anyone doing so.
Blue glass, lapis lazuli, blue spinel and other gems occasionally look like blue sapphires, but are easily detected by testing for hardness, specific gravity, and brightness.
The most rare and valuable of all blue sapphires is the maha-nila, which, when immersed in 100 times its own weight of milk, can tinge the milk blue.
Astrologically, fine blue sapphires are as powerful as excellent rubies, but monetarily they are valued at one-quarter the price of a ruby of equal quality. --- Sri Garuda Puranam: Chap. 72