Ruby is the red variety of corundum and is the sister stone of sapphire. Rubies symbolise love and in the past it was believed they possessed the power to bestow peace and harmony. Also the wearer of a ruby was thought to be protected from discord all perils of war.
If you were born in July, ruby is your special gem and that’s the perfect excuse to buy one.
Ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent color, excellent hardness and outstanding brilliance.
Natural ruby shades vary from light to dark red and they often have different undertones, such a purplish cast, but the variations add to the charm and individuality of each gemstone. Rubies are the red members of the corundum family of minerals.
Its name originates from ruber, Latin for red. Natural rubies are exceptionally rare, though artificial ones (sometimes called created ruby) can be manufactured which are comparatively inexpensive. Rubies are mined in Africa, Asia, Australia and Greenland. They are most often found in Myanmar, Sri Lanka and Thailand, though they have also been found in Montana and South Carolina.
The Alexandrite variety displays a color change (Alexandrite effect) dependent upon light, along with strong pleochroism. Alexandrite results from small scale replacement of aluminium by chromium oxide, which is responsible for Alexandrite’s characteristic green to red color 
Emerald is regarded as the traditional birthstone for May, as well as the traditional gemstone for the astrological signs of Taurus, Cancer and sometimes Gemini. One of the more quaint anecdotes on emeralds was by the 16th-century historian Brantome, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin America.
Diamond is the ultimate gemstone, having few weaknesses and many strengths. It is well known that Diamond is the hardest substance found in nature, but few people realize that Diamond is four times harder than the next hardest natural mineral, corundum (sapphire and ruby). But even as hard as it is, it is not impervious. Diamond has four directions of cleavage, meaning that if it receives a sharp blow in one of these directions it will cleave, or split. A skilled diamond setter and/or jeweler will prevent any of these directions from being in a position to be struck while mounted in a jewelry piece. 
