In Hindu mythology there are hundred types of gems worn by gods but out of them the following 84 are important to human beings.
Amongst them, nine–Ruby, Pearl, Coral, Emerald, Yellow or White Sapphire (Pukhraj), Diamond, Blue Sapphire, Gomedha and Cat's Eye-occupy foremost positions.
Five of them–Ruby, Pearl, Diamond, Emerald and Blue Sapphire—are termed as most superior gems and classed as semi-precious stones.
The eighty-four gems are:
1. Ruby or Maanaikya: This is of red colour and is a costly precious stone. Ruby is found generally in rosy, blackish and skylike colours. Sun favors this gem. It has to be more than 24 ratti in weight.
2. Diamond: This is also a costly stone and is found in yellow, white, red, rosy, blue, pink colours. This is a gem for Venus.
3. Blue Sapphire: This gem is found in ordinary or dark light blue colours. This is for Saturn.
4. Emerald: This is of bottle green colour and of tarnish white colour. It is Mercury's favorite.
5. Cat's Eye: This is yellowish or blackish in colour like that of cat. Inside this stone is visible a shining band A complete book on gems which moves when the stone is turned. Because of the quality it is also known as Sutra Mani. This is to please Ketu.
6. Coral: Generally Corals are found in red and light red colours. White Corals are also available. It invites power of Mars.
7. Pearl: This is of white light pink, yellow or black colour. Rosy coloured pearls are also seen. It attracts Moons favour.
8. Yellow sapphire: This is found in yellow, both dark and light, white and blue colours. Actually the one having blue colour becomes Blue Sapphire. It is also called Pushparage. This is Jupiter's favorite.
9. Turquoise: This is found in sky colour with a greenish tinge.
10. Gomedha or Neelam: It is like red coloured smoke. Its colour may be of honey or that of urine of the cow. This is Rahu's favourite.
11. Lalrhi: This has the colour of the rose petal or deep pink.
12. Opal: This is found in all colours. The one with white colour has also slight sparklings of other colours. It is a soft stone, a semi-gem of pearl.
13. Peridot: This has a very light green parrot like colour. It is used in place of Pearl.
14. Tourmaline: This is a soft stone and is available in red, green, brown and white colours. This is a very effective semi-gem stone and has many qualities.
15. Spinel Ruby: This is found in darkish and yellowish red colour.
16. Topaz: This is also called Citrine. This is found in light golden colour. But golden Topaz looks very attractive. It can be used in place of Yellow Sapphire. It is a favourite of Jupiter.
17. Amethyst: This is of light or dark violet colour. It is used to please Saturn.
18. Gold Stone: This is found in orange red, red colour with spots of golden colour. This is a very soft and weak stone. It is also called Sangsitara.
19. Rock Crystal: This is of shining white colour. If cut finely it looks like white Topaz. It is transparent.
20. Moon Stone: This has the colour of a white cloud or as the tooth of the cow. Inside the stone there is a glistening band which rolls when the stone is turned.
21. Romni: This is a soft gem of dark red colour with a blackish tinge.
22. Garnet: This is of blackish red colour. It is used in place of Ruby.
23. Ludhya: This is of deep red colour. It is a semi-gem of Ruby.
24. Maryam: This is of shining white colour.
25. Load Stone: This is also called Chakmak stone. This is of white colour tending to be blackish and produce fire when rubbed together.
26. Sindooria: This is of light rosy colour or pink with white tinge. It can be used in place of Corals.
27. Neeli: This is a soft stone and looks like Blue Sapphire.
28. Smoky Quartz: This is of smoky light golden colour. It can be used for Blue Sapphires.
29. Aquamarine: This is a gem of light green colour. It is mistaken for Emerald. Aquamarine is more transparent than Emerald and is much less expensive.
30. Jade: This is of green colour but without brilliance or lustre. It is a very cheap stone and is hard.
31. Blood Stone: This is of green colour with blood like red spots on it. It is a semi-gem of Emerald with often red spots.
32. Baanshi: This is a soft stone of green colour.
33. Durvenajf: This has the colour of unripe paddy. It can be polished.
34. Tursava: It is a soft stone of yellowish red or pink colour.
35. Ahwa: This is a stone of pink with spot in it.
36. Savore: This is a stone of green colour with a brown stripe on it. It is Emerald group.
37. Lapis Lazuli: This is a soft stone of blue colour. In ancient times in the Western countries this was recognized as Blue Sapphire.
38. Kudurat: This is of black colour with dots of yellowish and whitish colour.
39. Chitty: This is a stone black in colour with a stripe of gold like colour. It is a semi-gem.
40. Suleimani (Onxy): It is a gem of black colour with a white stripe on it.
41. Alaimani: It is of grey colour; belongs to the Suleimani family.
42. Jajemani: It also belongs to the Suleimani family. It is of grey colour with a white stripe on it.
43. White Jade: This is a white stone with the hue of graphs and other colours.
44. Laroo: This is a kind of marwar stone.
45. Marwar: This semi-gem of Coral is found in three colours—bamboo like, red and white.
46. Kidney Stone: This is of light green colour like that of pista.
47. Halan: This is a stone of rosy colour. The colour rolls when the stone is moved.
48. Seejri: This is a stone of white colour giving the impression of tree on its body.
49. Kasauti: This is of black colour and is used for testing the purity of gold.
50. Darchana: It is of the colour of cinnamon.
51. Haqiq-al-bahar: This comes out from watery places. The colour of this stone is yellowish green. Necklaces are generally made of it.
52. Mubenjaif: This is a stone of white colour with hair-thin black line or lines.
53. Amber (Kahruba): This is of dull whitish colour or red.
54. Jhana: This is a very soft moon stone. A touch of water destroys the stone.
55. Sang-Basri: This is used for making surma (a medicinal grey powder) for eyes. It is a favorite of Saturn.
56. Daantla: This is of yellow colour, looks like old couch-shells.
57. Makhra: This is a black stone with an impression of spider's web on it. It is used to appease Saturn.
58. Sangeeya: This is of white colour like conch-shell.
59. Gouri: This is also available in various colours and forms, generally used by mendicants. It has white stripe. This is used for making measuring weights for the jewelers.
60. Seeya: This is of the black colour used for making statues.
61. Somaack: This is of red colour with a yellowish tinge. There are rosy coloured sprinklings on it. This is used for making mortars in which medicines are grinded.
62. Goodri: Now-a-days this is a favourite stone in Muslim religion. It is of grey colour.
63. Kamla: This is of whitish green colour.
64. Cyphery: Its colour is like a mixture of green and sky blue; it is a gem of Saturn.
65. Hareed: It is grayish black. It is used for making rosaries.
66. Havvas: This is of green colour with a golden tinge. It is used as medicine.
67. Seengli: This belongs to the Ruby family, but it is much softer and inexpensive. This is of red colour inclined to brackishness.
68. Dhedi: This is of black colour used for making cups and saucers, etc. Idols and garlands are also made of it.
69. Agate (Hakeek): This is found in various colours. It is a very inexpensive but lasting stone. It is considered very auspicious. It is also used as a birth stone.
70. Moosa: White dusty colour, used for making bowls.
71. Pandhan: Black with greenish tingo, used for making toys.
72. Amleeya: It is of pink and blackish colour used for making mortars.
73. Door: It is of pale brown colour like catechu, used for making mortars.
74. Liliar: It is of black colour used for making mortars.
75. Khaaraa: It is of black colour with green shades and is used for making mortars.
76. Paaraa Jahar: It has the colour of a white bamboo. It has great medical properties in healing wounds.
77. Gypsum: It is of dusty colour like clay. It is used in making dolls.
78. Paras: If it touches iron, it is turned into gold. This is a rare stone and nobody has acquired it.
79. Zahar Mohra: Greenish in colour, it is believed that if poison is put in a cup made of this mineral, it loses its evil effect.
80. Ravaat: This is found in red and blue colours, but red one is important. It is used to lower temperature if fixed in arm pit.
81. Sohan Makhkhi: Looks like white clay. It is considered useful for urinary troubles.
82. Hazrat-e-oodh: Black in colour, it is used for making medicines for eyes in the Unani system of medicine. It appeases Saturn.
83. Surma: It is of black colour. Its powder is applied in eyelids.
84. Godanta (Cow's teeth): Found in cow teeth colour with yellowish tinge. It is used to appease Rahu.
According to Indian gemology all these have been recognized as such.
It is possible that many of them may be known in various countries by different names.
From amongst the eighty-four gem stones mentioned above, all are not related to the planets. The main gem stones suitable for use for remedial purposes for planetary affliction are nine–Ruby. Pearl, Coral, Yellow Sapphire, Emerald, Diamond, Blue Sapphire, Gomedha and Cat's Eye.
The stones that can be used for planetary afflictions because of their colour, luster and the beliefs, durability, hardness about them are as follows: Topaz, Spinel, Turquoise, Moonstone, Garnet, Neeli, Aquamarine, Jade, Blood Stone, Lapis-Lazuli and Agate.