Ancient books have given details of all the gems, but Varahamihir, one of the greatest ancient scholars, in Ratna Dipika, has mentioned only 22 types of gems. They are given below:
Agate Methodist, Azure Stone, Blood Stone, Blue Sapphire, Brahama man, Cat's Eye ,Conch, Coral, Crystal ,Diamond, Emerald ,Jyoti Rasa, Moon Stone, Opal, Pearl, Rasmani ,Ruby, Sasyara, Saogandhrika, Vimlara, Yellow Sapphire
Some important gems according to the saint:
Diamonds found on the banks of Vena River were of the purest kind. Those mined in Koushala had the lustre of the Sirisa flower, those from Saurashtra had a reddish lustre, those from Saupara country were dark in colour, those from the Himalayan regions were slightly reddish, those from Matanga country had pale white colour, those from Kalinga were yellowish, and those from Paundra were black.
It is difficult now to locate all these places with the above names, but it does prove that mines of gemstones were in existence in India in ancient times.
According to many ancient religious books Diamonds are presided over by gods.
A white hexagonal Diamond is presided over by Indra, a dark one of the shape of the snake's mouth by Yama, one with the bluish yellow colour by Vishnu, one having the colour of karnikara flower by Varuna, a triangular one of the colour of tiger's eye by fire, one having the shape of barley corn and the hue of Ashoka flower by Vayu.
Diamonds have been divided caste wise also. White Diamonds are auspicious for Brahmins, red-yellow ones for Khatriya, those of whitish yellow colour by Vaishyas and those with dark colour for Shudras.
A Diamond is believed to be beneficial to its owner, if it cannot be cut by any other substance, is light, cleaves through water like a ray of light and does not change its lustre to lightening.
The Diamonds that show scratches, are mixed with coloured substances and have double facets are burnt.
Perforated, discoloured, lustreless, covered with bubbles, split at the points and oblong in shape are treated as inauspicious.
According to Varahamihir Rubies are born of sulphur, kurvinda and crystal. Those got out of sulphur exhibit the lustre of bees, lily or rose apple. Those that are got from kuruvinda are of pale lustre and mixed with mineral substances, and those from crystal are multi-coloured, lustrous and pure.
The general qualities of all excellent Rubies are lustre with rays, purity, smoothness, sparkle, heaviness, fine shape, brilliance within and existing bright redness.
Stones are defective if they are of dull lustre, full of scratches, mixed with mineral substances, broken, not attractive and mixed with gravel.
The Ruby obtained from the head of a serpent which has the hue of a bee or peacock's neck and which shines like the flame of a lamp is of inestimable value.
Anyone who wears such Ruby will be a multi-millionaire; he will never be defeated anywhere and will lead a royal life. Ruby is the most wonderful gem.
Pearls are from conch shells, serpents, elephants, pearl oysters, clouds, bamboos, whales and hogs; the best one is the one which comes out from pearl-oyster.
Eight types of Pearls have been mentioned by Varahamihir :
(3) Saurash' a
(4) Tamraparni river
(6) a northern country
(7) Pandya Vataka and
(8) the Himalayas.
The Pearls from Simhalaka were glossy, multi-shaped, swanwhite and large and bright, those from Parloka were blackish, white or yellow and were uneven, those from Saurashtra were neither big nor too small and with the lustre of butter; those from Tamraparni river were white with a slight red tinge, those from Parusava were lustrous, clear, heavy and very valuable and of superior quality, those from the northern country were rough, black and white, of good size and brilliance, those from Pandya-vataka were like the neem fruit and very small in size and those from Himalayas were light, curdlike in appearance, large and double-shaped.
Dark Pearl is for Vishnu, one like the moon for Indra; yellow for Varuna; black for Yama; red for Vayu and one having the brilliance of smokeless fire or the lustre of lotus for Agni.
Very valuable and lustrous like moon was the Pearl born of the root of elephant's tusks.
The Pearl obtained from whales resembled a fish's eye, Was large, pure and of great value.
I was said that the Pearl was produced in the clouds of seventh layer of the wind in the sky in the manner of hail stones. Such pearls never reached the earth. A Pearl got from the serpents is valuable. It destroyed all misfortunes and enemies and enhanced reputation.
The Pearl from bamboo was flat and uneven, and that from conch was round, lustrous, and moonlike.
All the above categories of Pearls were considered to be extremely valuable and were believed to bestow popularity, wealth, renown on the wearers, and were destroyers of grief and diseases.
It is said that an Emerald of the hue of parrot's wings, bamboo leaves, banana trunk and of good quality with smoothness and purity was highly beneficial to people when they wore it at ceremonies performed in honour of gods. Some of them are used as birth stones.