Red Burmese ruby 3.34 carats

Ruby is a pink to blood—red gemstone, a type of the mineral corundum (aluminum oxide). Other varieties of jewelry-grade corundum are called sapphires. Ruby is considered one of the four precious stones along with sapphire, emerald and diamond.

The word "ruby" comes from the Latin ruber, which means "red". The ruby's color is due to traces of chromium in its composition. Some cabochon-cut rubies have a star shape due to the reflection of light.

Rubies were used as currency and jewelry as early as 600 BC. Rubies were found in Sri Lanka as early as 300 BC, but until the XVIII century AD, most of them were mined in Burma. The Burmese ruby is considered the most expensive red gemstone in the world after red diamonds. The hardness of ruby on the Mohs scale is 9.

Burma is the oldest source of rubies, and it was very difficult to get them in good quality. Due to the chromium content, Burmese rubies have a fluorescent glow.

Burmese rubies are still considered one of the most expensive gems in the world.