Sapphire :
Sapphire is a gemstone of the family of the mineral corundum. The most famous color for Sapphire is blue, but trace amounts of other elements can give yellow, purple, orange, or greenish sapphires.
In the case of chromium impurities in corundum it would be called a called a Ruby. Sapphires are found in Sri Lanka, Myanmar or Australia.
Carat :
The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.
Platinum :
Platinum is the most precious metal on earth. unlike gold that is too soft to be used whithout being alloyed with 25% of other metals, platine can be used 95% pure. It extremely white color is appreciated for setting extremely pure diamonds.