Sri Lanka is not only the most productive source for sapphire but the sapphire mines here are among the oldest known. According to historical accounts, Ceylon was already known for sapphire by the 2nd century A.D. and there was an active international trade in Ceylon gems by the 4th and 5th centuries. Many of the most famous sapphires in the world come from Sri Lanka. Ceylon sapphire has been valued for its vivid color, which tends towards a lighter and brighter blue than the dark blue sapphires from other sources.It was once called Rathnadweepa which means Gem Island in Sinhalese. Persian traders endearingly referred to the island as Serendip; presumably, because the discovery of such magnificent treasures leads to happiness, good fortune, and luck.  

9/10 of Sri Lanka is made of high-grade metamorphic rock which means the 90% of Sri Lankan landmass belongs to Precambrian age is aging 3000 to 4000 Million years forming the very first layers of the earth. 

Sapphire is the birthstone for September and the gem of the 5th and 45th anniversaries. Also before doing any research about sapphires & certification, we all need to understand that gemological labs do not grade but assess the characteristics of a sapphire (weight, measurements, shape, cutting style and color), determine natural or synthetic, indicate detectable treatments such as heat treatment (completely a natural process), and then issue an opinion on the geographic origin on a Gemological Identification Report. 

When it comes to colorless diamonds, the stone is completely graded from color, clarity, cut, fluorescence, weight, etc. Making it a completely different story. 

Every mine produces a wide range of quality gemstone. For gems of exceptional quality, an independent determination of origin adds to value. For sapphire, Kashmir receives the highest premium although Burma, Sri Lanka, and Madagascar also produce top-quality gems. 

Sri Lanka is the only country that currently produces top-quality cornflower to peacock blue sapphires in volume-wise compared to Burma & Madagascar making the Ceylon sapphires to be the pilot in the gemstone industry in 21^st Century. The tight chemical bonds of corundum also make the stones very dense and relatively heavy. This means they have not swept away during weathering, but accumulate in alluvial deposits – that is, left behind by the flow of water. As a result, sapphires can be found by miners tunneling down to ancient riverbeds or in bends of existing river beds.