Diamond or Heera (for Venus)
It is said that the one who wears a Diamond has a luxurious life . Diamond is also supposed to enhance the name, fame and artistic quality of the person. Diamond is a hot gem. It creates goodness and removes evil and fearful thoughts in the native. It improves financial conditions and blesses the native with comforts and peace of mind. It also enhances sexual power. Also helpful in diabetes, diseases of urine, of private parts, syphilis, skin and uterine diseases. Diamond should he worn on 1st finger of right hand on Friday in gold or platinum. The weight should be 1/4 or 1/2 gram.

Physical properties
The name diamond comes from the Greek 'adamas', meaning 'invincible' in recognition of its exceptional hardness which makes it resist any form of abrasion by other minerals. Diamond is carbon in its pure form. Chemically there is no difference between diamond, coal and graphite. But the unique atomic bonding makes the difference. It has a specific gravity of 3.52, mean Refractive Index is 2.418 and has a hardness of 10 on the Moh's scale.

Occurence
Diamonds are found in South Africa, Australia, Russia, Kenya, Ghana, Angola, Tanzania, Brazil and India. In India Diamonds are found in Madhya Pradesh, Orrisa and Andhra Pradesh.

Identification
For a Diamond to be real, it must possess some inclusions. These inclusions are visible by naked eye or under magnification. If no inclusions, black spots or milk patches, are visible in a Diamond then either it is a zirconia or piece of glass. Diamonds which do not have any inclusions under 50x magnification are very rare and can be found with collectors only. The small black spots visible in Diamonds are crystals of Graphite or other forms of Carbon. These black spots shine under light. Diamonds have an affinity for grease, the surface of a cut Diamond will generally have a film of grease if it had been handled.

The most important test of a diamond is that, all light entering the front of the stone is totally reflected from the back facets which form a series of mirrors. A well cut diamond if viewed from the back and held up to the light, will show only a pinpoint of light from the culet.

In addition, looking down on a brilliant-cut diamond one cannot see the wearer's finger below the stone, as can be seen in other stones. White light entering a diamond is dispersed into a spectrum of colours, giving flasks of different colours from the smaller crown facets.

Zircon or Gomedh or Hessonite (for Rahu)
The shadow planet Rahu is supposed to be responsible for all sorts of delays or very late fulfillment of ambitions. Gomedh can help in achieving speedy success in less time than expected. Gomedh also improves dealing with people and protects its wearer from sudden misfortunes. This is normally reddish-chocolate in colour. Gomedh is cold in nature. It cures diseases caused by affliction of Rahu and Saturn. It also increases appetite, vitality, confers good health, wealth and happiness and all round prosperity. It is said to be the best gem to avert stomach ailments, disaster, insanity, and evil spirits.

It should be used in silver on Saturday on 2nd finger of right hand. The weight should be 6, 11, 13 grams.

Physical properties
Its name comes from Greek 'esson' meaning 'inferior', since these gems are supposed to be less valuable. Gomedh is a Gem of the Garnet family. Magnets can pull these Gems, which is a very special phenomenon, as magnets otherwise pull only certain metals. Chemically it is known as Grossular (3CaO.Al2O3.3SiO2). It is found in number of colours like green and pink but generally it is orange brown. It has a hardness of 7.25 on the Moh's Scale, specific gravity is 3.65 and Refractive Index is 1.74.

Occurence
It is available in abundance. It is found in India, Sri Lanka, Brazil, Australia, Tanzania, South Africa, Burma, Mexico, Russia, Italy, Kenya, Canada, U.S.A, and Malaysia. In India it is found in Andhra Pradesh, Orissa, Rajasthan and Bihar. Gaya mines in Bihar are the biggest source of this gem. Recently, very good quality of this Gem has been found in Orissa.

Identification
This Gem contains inclusions which look like scattered islands or flat bubbles. The colour is like honey shining under a ray of light. The inside, when viewed under magnification looks like a thick sticky liquid and certain areas look out of shape with lesser transparency.