Adding some details about Kohinoor diamond. It was first mentioned in 1306 while it was in possession of Rajah of Malwa and at that time it apparently weighed 186 carats the shape and size of a small Hens egg.From 1306 it has changed hands many times , gone into the possession of Mughal Kings and Hindu rulers. Babar had it for some time and Shah Jehan had it placed in his ornate Peacock throne. It became famous and known worlwide when a French traveler, Jean Baptiste Tavernier, who was an expert at valuating diamonds wrote about Kohinoor calling it The Great Mughal because it was in the hands of Mughal Kings.
Finally it landed in the hands of Ranjit singh and Governor Dal Housie was responsible for manipulating the weak Sikh empire and taking possession of Kohinoor. To make it look like a gift he arranged that Ranjt singh's successor Duleep Singh should present it to queen Victoria , who was the empress of India , then.
In 1852 the Kohinoor was re cut to increase its brilliance and mounted in a tiara with other smaller diamonds .
The mysterious curse that the diamond has - 'He owns the diamond has the world , will also know all its misfortunes. Only God or a woman can wear it with impunity " It is not sure how and when this curse originated but there is violence and bloodshed among all male royalty that took possession of the diamond. Britishers knowing about this made sure that it was worn by their reigning queen..
http://themystery2012.blogspot.in/2012/07/kohinoor-diamond.html