Ruby or Manik (for Sun)
Ruby is said to give name, fame, vigor, virtue, warmth and the capacity to command to its user. It can also raise the individual far above the status in which he was born. Historically, it has been symbolic of love and passion. This is normally red in colour. Ruby is a hot stone.

On diseases front: Ruby helps cure peptic ulcer, fever, rheumatism, gout etc. However prolonged use may cause boils, itch and insomnia as well. Do consult an astrologer or a gemologist before wearing this or any other stone. Ladies should avoid the use of Ruby as it can destroy the body lustre.

Ruby should be used in gold in third or ring finger of right hand on Sunday. Ideally should be of about 3 or 5 grams in weight.

Physical properties
The name Ruby comes from Latin 'Rubrum', which means 'Red'. Ruby, which is corundum, is simply crystallized alumina (Al2O3) and in pure form it is devoid of colour. The rich colour in Ruby is mainly due to small amounts of chronic oxide, which is able to replace part of alumina without disturbing the trigonal crystal structure. It has a specific gravity of 3.99. Mean Refractive Index is 1.765 and the hardness is 9 on the Moh's scale.

Occurrence
Ruby is found in Burma, Thailand, Sri Lanka, East Africa, Kenya, Nepal, Afghanistan, India and Pakistan. The best Rubies are from the Magok district of Burma. Thai Rubies are comparatively less attractive and the Rubies found in Sri Lanka are pink.

Identification
Natural Rubies are never 'clean' i.e., without inclusions. They contain inclusions which look like 'silk'. Natural Ruby encloses small crystals of other minerals, in the form of pale angular grains, cavities of irregular shapes, patches of fine needle-like criss-crossing canals which give a silky effect by reflected light. If these inclusions are not visible to the naked eye, then the eyeglass should be used to detect them. If even under high magnification no such inclusions are visible, then the Gem you are checking is most probably a piece of glass. A synthetic Ruby will either not contain any inclusions or else it will have bubble-like inclusions, or cracks, as seen in a glass, will be visible. The cracks will give a milky hue and will be of an even nature.

Emerald or Panna (for Mercury)
Emerald improves faculties related to the brain such as memory, communication, intuition, the intellect, and the ability to learn. It is normally petal green or dark green in colour.

Emerald is a hot gem. It increases intelligence and brainpower, removes and cures fickle-mindedness, loss of memory, stammering, fear from souls and spirits, cools the harsh speech. One of the interesting observations about Emerald is that it is not prescribed for newly wed couples. It is said that newly married couples should not use it, as it impairs conjugal happiness due to reduction in sexual desires. It is also useful for curing diarrhea, dysentery, gastritis, peptic ulcer, asthma, insomnia, heart troubles, etc. Emerald should be used in gold of 3, 5, 7 or 10 grams on 4th finger of right hand on Wednesday. An Emerald wearer is likely to find sufficient wealth.

Physical properties
Emerald, which is a Gem of Beryl family, is a silicate of beryllium and aluminium 3BeO.Al2O3.6SiO2. The colour of Emerald is mainly due to traces of chromium replacing aluminium ions in the hexagonal beryl crystal. It has a specific Gravity of 2.71, mean refractive index is 1.58 and hardness is 7.5 on the moh's scale.

Occurrence
Emerald is found in Colombia, Brazil, Russia, Tanzania, South Africa, India, Australia, Austria, Pakistan, Kenya and Zambia. In India, Emeralds are found in Rajasthan, Orissa and Madhya Pradesh.


Identification
Emeralds from various mines have different kinds of inclusions. These inclusions can be seen with the naked eye, or else under magnification. If no inclusions are seen even under magnification, the chances are that the Gem under examination is either a piece of glass or a fake. The inclusions in Emeralds include flakes of mica, inclusions like fibre, milky white spots, straw and bamboos and small cubes of rock salt are also seen sometimes. Black spots are also seen in Emeralds. Emeralds were formed when lava coming out from the volcanoes solidified on the surface of the earth. At this stage its fast solidification led to certain flaws in its crystal formation and certain foreign elements also got into it. The synthetic Emeralds contain nail-like inclusions, brush-marks or chains of bubbles.

Red coral or Praval or Moonga (for Mars)
It is said that Red Coral instills courage in its wearer. It also helps in curing blood -related diseases. It is normally red in color. Coral ensures material happiness, recovery from diseases indicated by Mars such as fever, cough, bilious complaints, smallpox, chickenpox, headache, loss of vitality, piles, boils, measles etc. It should be worn in silver or copper, and should be of 9, 11, 12 grams, on Tuesday on 1st or 4th finger of right hand. It is a hot stone.

Physical properties
Coral is a product of sea. It is formed from the calcareous skeletons of myriads of tiny polyps (which means insect with many feet) which live in vast colonies in warm waters at a moderate depth. It is composed chiefly of calcium carbonate. This is arranged as fibres radiating from the central axis of the curving coral branches. Its specific Gravity is 2.68 and hardness is less than 4 on the Moh's scale. It is an opaque stone. Many forms of coral exist but only high quality Red, Pink, Blue, Black and white corals are used in jewellery.

Occurence
Corals are found in India, Italy, Australia, Sri Lanka, Japan, Malasia, South, Africa, Algeria and U.S.A.

Identification
Coral, being an opaque gem, is very difficult to identify. A lot of eye practice is required to differentiate between a natural and a manmade coral. Natural corals, if seen under magnification, always tell the story of their origin. They have black marks which are actually holes.

A very careful examination is required to identify a natural coral. As real corals are not very clear and if clear they are very costly. Manmade corals are very commonly found in the market places being sold as real corals.