Being arrested and bound by the demigods, Vala emitted a thunderous war cry. This war cry transformed into the seed of the gem cat's eye.
Falling into the sea, these seeds agitated the ocean and produced huge waves which washed them upon the shore of nearby lands. wherever they settled they formed mines of shimmering cat's-eye. Many of these mines are near Sri Lanka's famous Vaidurya Hill and so the gems came to be known as Vaidurya stones.
That terrible war cry of Vala also carried heavenward and impregnated the clouds and the sky. Later, carried to earth by rain and comets, these sees formed smaller mines of cat's-eyes in scattered areas.
The most precious cat's-eye are golden green like the breast feathers of the peacock or light honey-green like a bamboo leaf. When these primary colors are mixed with shades of brown or burgundy, the gem is less valuable.
Gems such as apatite, tourmaline, and enstatite are sometimes mistaken for true chrysoberyl cat's-eyes, but can be differentiated by their lesser hardness. Other imitations, such as glass or quartz, are easily detected by their relative lightness or low specific gravity.
The value of a true cat's-eye varies according to its color, clarity, and shape, A cat's-eye of excellent quality mined near the sea in Sri Lanka should be considered more valuable than an ordinary cat's-eye. The value of cat's-eye is approximately one third the value of similar quality blue sapphire. ---Sri Garuda Puranam: Chap. 73