The blood of the high and mighty demon Vala was taken by Surya, the sun-god, who then fled into the blue vastness of space. Ravana, the great king of Sri Lanka, who was puffed up with his power and his victory over the demigods, attempted to block the sun-god's flight in the sky like a solar eclipse. Appearing terrified of Ravana's fearsome presence, the Sun-god dropped the demon's blood, which fell down into the deep pools of Bharata which were surrounded by forests of betel nut trees and scintillating with sunlit waves. (Bharata or ancient India, as referred to in the text, included Burma, Siam, Afghanistan, Pakistan, Nepal, Tibet and of course, Sri Lanka.)
From that time on, these pools became as holy as the sacred Ganges River and were known as Ravana-Ganga. The banks of these waters became covered with precious gemstones, all sparkling with dazzling splendor. Beautiful and effulgent rubies, as well as other colors of corundum, possessing manifold virtues, are the gemstones which originated on the perfumed shores of Ravana-ganga.
The rubies from these fragrant lands are found in a variety of hues. Some are red like human blood, while others resemble the red of pomegranate seeds. Some rubies are vermillion red and others are yellowish-red like saffron or shellac dye. These should be evenly colored with light shining from their very core. Being illuminated by rays of the sun, this crystal species shines forth with wonderful color and brilliancy, reflecting in all directions and spreading rays all around.
Kuruvinda rubies are not so purely colored as those rubies of the "top crystal" quality and are somewhat lacking in clarity and luster. (According to Apti's Sanskrit/English dictionary, both kuruvinda and padmaraga are names for ruby. But in the context of this book kuruvinda refers to rubies of inferior color and clarity while padmaraga denotes rubies that possess the finest (purest, unmixed) color and top crystal clarity. In this text, rubies of the finest quality are called padmaraga, "lotus-hued" while poorer quality rubies are referred to simply as kuruvinda "corundum." It may also be noted here that the English name for corundum was derived from the ancient Sanskrit world kuruvindam).
The most important features of a "top crystal" quality ruby are: (1) purity of color; (2) heavy specific gravity: (3) coldness of touch; (4) flawless and transparent clarity; (5) brilliancy; and (6) excellent proportions. The value of a ruby is based primarily upon the purity of color and brilliancy. Any decreases in either of these qualities causes a proportionate decrease in value.
The potency of a high-quality ruby is such that even an ignorant person living a sinful life and surrounded by deadly enemies is saved by wearing such a gem. Anyone wearing such a naturally effulgent ruby would be freed from diseases caused by any imbalance of the bodily functions. Faults that characterize lower quality rubies are: A coppery tinge, silky inclusions, cloudy or oily appearance, dullness, off-color and excessive darkness around the edges (girdle) when the stone is held between the fingers (covering table and culet).
A potential ruby of exceptional quality should first of all be tested for specific gravity against a known ruby of the same size. A specimen which proves to be considerably lighter than the genuine ruby indicates that it belongs to another mineral species.
In a situation where the results of testing proved inconclusive, one should use the scratch test, scratching the specimen with a known ruby. No other mineral except diamond or corundum can scratch a peace of genuine ruby or sapphire.
A genuine ruby possessing all auspicious qualities should not be worn together with a gem of imperfect or flawed features or one belonging to a species that is astrologically incompatible with it.
One is advised not to wear a gem of poor quality or that is incompatible even if it is set together with the divine Kaustabha jewel. For as a host of saints lose their status by association with a single impure outcast, in the same way even one low quality or incompatible stone can spoil and entire setting of precious gems.
A ruby, although genuine, should not be worn if it has strong color banding, excessive inclusions within like numerous internal cracks, a sandy appearance, a rough surface, or is dull and lusterless. Anyone using such a flawed ruby, even out of ignorance, will suffer from disease, or loss of fortune. ---Sri Garuda Puranam: Chap. 70