Hindu mythology has classified gems into three groups: gems belonging to heaven (Swarg lok), gems belonging to earth (Mrityu lok) and gems belonging to hell (Patal lok).
The gems belonging to heaven are worn by gods. The four important gems belonging to Swarg lok are:
Brahma (the creator) wears Chintamani a white stone.
Vishnu (the preserver) is adorned with Kaustubhamani a bright gem, which is lotus coloured and which radiates rays like the Sun.
Shiv (the destroyer) is associated with Rudramani, a golden gem.
Indra (the ruler of Swarg lok) wears a brilliant blue gem, Syamantakamani.
The patala lok and its inhabitant's serpants and demons have their own precious stones
in black, blue, yellow, green, white, red, pink and milky colors. All gems and semi-precious stones known to man form the gems from mrityu lok or earth.
Although traditional Indian gemologists have identified 84 precious and semi-precious stones, amongst them 9 stones namely: Ruby, Emerald, Pearl, Diamond, Red coral, Zircon, Blue sapphire, Yellow sapphire, Cat's Eye form the Navratnas or nine gems.
Navratnas Ruby: Pink red colored stone, known for its brilliance and radiance. Usually made up of crystals of six sided prisms. It is highly valued as it is said to represent the Sun god (Surya), who is the master of the universe. This stone signifies power, authority, good health, father etc and is said to have a positive effect on the health and destiny of a person wearing it. Jewelry and ornaments studded with ruby are very costly.
Emerald: Bright green colored stone. It is the representative of plant Mercury (Budh) and affects knowledge and learning. Like ruby, flawless and radiant emeralds are considered the best. Rajasthan is known for emerald mining. Udaipur and Ajmer are main centers of emerald mining. Emeralds from Udaipur are dark and hard, while the ones from Ajmer are pale. Emeralds are used in Kundan jewelry and the green colored Meenakari done on the reverse side of the ornaments often matches their brilliance.
Pearl: A spherical organic material, obtained from oysters. Pearls come in a variety of shades ranging from white, off white, pink, red, brown, creamy etc. In traditional Indian astrology it holds an important place and is referred to as the queen of the sea and represents the moon god (Chandra). Pearl is said to have a soothing affect on the person wearing it and signifies purity and dignity. Andhra Pradesh and Tamil Nadu are main pearl fishing centers. Traditional necklaces, earrings etc made out of pearls form the traditional jewelry traditions of Maharashtra and Hyderabad.
Diamond: It is the hardest known material found on earth and the most precious of all stones. It is graded according to its color, size, hardness and the degree of refraction.
The diamond represents Venus or Sukra and it brings beauty, wealth, and prosperity to the person wearing it. The state of Gujarat in general and Surat in particular is known for diamond cutting and polishing worldwide. 8 out of every 10 diamonds used in jewelry worldwide have been cut and polished in India.
Red coral: Coral is obtained from coral reefs and generally comes in red or vermilion color. It is made up of organic material from dead minute sea organisms. It represents planet Mars or Mangal and controls activity, energy, ambition and dynamism. Red coral is often worn in necklaces, amulets and rings. The coastal regions of India are known for ornaments made from red coral.
Zircon: A smoked red or dark honey colored stone. Chemically it is a silicate of zirconium and crystal and occurs as a four-sided prism. It is also known as Gomedha, which represents Rahu, the ascending node of the moon. In India it is found in Kashmir, Bihar, Kullu, Shimla and Coimbatore. It is representative of worldly desires and aspirations, laziness etc. It is not considered auspicious and is worn to ward the evil effects of Rahu, which is also known as 'head of the celestial dragon'.
Blue sapphire: A navy blue brilliant stone. It is also referred to as Neelam and represents planet Saturn or Sani. It influences on one hand good things like long life, ambition, prosperity, leadership, wealth etc and misery, accident, failure, adversity on the other hand. As the effect of this stone is highly temperamental, it should be worn under proper guidance of the astrologer. The best and the brightest blue sapphires come from Kashmir and are called 'mayur neelam' because of their peacock blue colour.
Yellow sapphire: A yellow or pale white stone. It is also known as Pushparaj and represents planet Jupiter or Guru. It signifies knowledge, philosophy, religion, virtue, future, distant travel etc. It is said that the person wearing yellow sapphire is bound to have a increase in his mental and intellectual abilities.
Cat's Eye: It is yellow or black colored stone with a shining band, which is similar to the eye of a cat. It also known as sutramani and vaidurya. Cat's eye represents Ketu or 'tail of the celestial dragon', the descending node of the moon god (Chandra). Its influences are similar to those of Mars or Mangal and include ascetism, liberation, enlightenment, non-attachment etc. In India this gem is found in Tiruvananthapuram in Kerala.
Traditional Indian gemologists have identified 84 important gems, some of the important ones being:
Aabri : a black-coloured stone.
Ahwa : rose colored.
Alaimani : brown in color, belongs to the Suleimani family. The word translates as'temple bell' in Tamil.
Amleeya: dark rose, used for making mortars.
Banshi : a soft, green stone.
Bairooz : aquamarine, light green.
Chadrakantamani : or godanta or moon stone, as the names suggest, has the color of white cloud or the tooth of a cow. There is the glistening band which rolls when the stone is turned.
Chitti : golden-colored, with a stripe.
Dana phirang : kidney stone, light green in color.
Darchana : color of the yellow pulse.
Dhedi : black, used for making crockery.
Door : dark brown, also used for mortar.
Dantla : yellow.
Durvenjphj : color of unripe paddy.
Ghunela : smoky quartz, also gold in color.
Gouri : comes in various color, often has white stripes, used for making measuring weight for jewellers.
Halan : its pink color moves when the stone is moved .
Haquiq-al-bahar: has it for making eye medicines.
Haree: black-brownish, used for making rosaries.
Hawas: green with a golden tinge.
Jabarjad: light green pari dot.
Jamuniya or kataila: amethyst, light or dark purple in colour, also a birthstone.
Jajemani: also of the suleimani family, brown in color with a white stripe.
Jhana: a very soft stone which even water can destroy.
Kehruva: amber, dull wheatish.
Kasauti: lit. Tough stone use to test the purity of gold.
Kamala: dull white with a green tinge.
Khara: greenish, used for making mortar.
Kudrat: black with yellow and white spots.
Lalri: the color of the rose, also called gulabi.
Ludhia : red stone.
Lajvart: lapis lazuli; a soft blue stone known in the west as the blue sapphire.
Laroo: a kind of marvar stone.
Liliar: black, used in mortar.
Mariyam: of shining white color.
Makanatees: lodestone, also called chakmak, its color ranges from white to black.
Margaj: jade, green inexpensive opaque stone with astrological signifcance.
Marvar: in three colors, red white and offwhite.
Makra: meaning spider, the black stone has the impress of a spider's web.
Moosa: dusty white, used for making bowls.
Naram: a dark yellow-red spinel ruby.
Neeli: a soft stone which resembles the blue sapphire.
Opal : opal, a popular multi-hued sparkling gem.
Pitania: blood stone, green with blood red spots.
Panghan: black, used for making toys.
Para zahar: color of white bamboo, has great medicinal properties, properties, healsheals wounds quickly.
Parasmani: a legendry stone very rarely seen, it is said to have an ability to turn base metals in to gold. Alchemist's stone of western legends.
Romni: soft black red-stone.
Rawaat: red and blue, both with medicinal properties.
Sitara: gold stone; orange red with specks of gold, very soft and brittle.
Sphatik: rock crystal, shining white. Cut finely ,this resembles white topaz.
Sindooria: light pink.
Savore: green with white stripe.
Sangson: white with impress of a tree.
Sang-basri: used for making surma.
Sangeeya: white stone.
Sifiri: a mixture of green and sky blue.
Seengli: belongs to the ruby family but is softer and less expensive, the color tending towards black.
Seeya: black, often used for sculpture.
Seemark: red with yellowish tinge, used for making mortar in which medicines are triturated.
Seer khadi: gypsum, dusty appearance, used for making toys.
Sohan makhkhi: looks like white clay, considered effective in curing urinary troubles.
Surma: lit.khol, to line the eyes, black.
Sunehal: topaz, also called citrine; golden topaz is most attractive.
Surma: black with a white stripe.
Turmali: tourmaline, soft stone in a range of color, has great astrological significance.
Tamda : garnet, black, redor maroon, almost popular semi-precious stone.
Tarawa : soft yellow-red.