Mini Chivor pendant Aurélie Bidermann in yellow gold and blue sapphires

18k yellow gold (750 thousandths) is 75% pure gold, alloyed with other precious metals to make it workable. It is the most beautiful quality of gold that can be found in jewelry.

Also known as 18k gold.

Like ruby, sapphire is a precious stone belonging to the corundum family. Its blue color, the most common for sapphire, is due to the presence of iron and titanium in its chemical composition. Pink, orange, green and yellow sapphires are also available. On the Mohs scale (a scale for measuring the hardness of minerals, ranging from 1 (the lowest, like talc) to 10 (the highest, like diamond), sapphire has a hardness of 9.