Rubies are given to those who were born in July. It is also the 40th anniversary gemstone, because rubies are thought to possess an eternal inner flame which is a symbol that the passion in a marriage is still very alive and strong after 40 years together. The ruby stands for courage, integrity, happiness and devotion. It is the red variety of the mineral corundum, colored by the element chromium.
All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics. The ruby is a tough and durable gem. The only natural gemstone harder than a Ruby is a Diamond. Despite this, rubies are still subject to chipping and fracture if handled roughly, and care should be taken to ensure it is properly handled.
The quality of a ruby is determined by its color, cut, and clarity, which, along with carat weight, affect its value. The brightest and most valuable shade of red called blood-red or pigeon blood, commands a large premium over other rubies of similar quality.