Heliodor gets its yellow color from the presence of iron impurities in the crystal lattice structure of the beryl. The intensity of the color can vary depending on the amount of iron present, with some specimens being a pale yellow and others being a deep golden yellow.
Heliodor has a hardness of 7.5-8 on the Mohs scale, which makes it a durable stone that is suitable for use in jewelry. However, it is also relatively brittle and can be prone to cracking, so care should be taken when cutting and polishing it.
Heliodor is found in several locations around the world, including Brazil, Madagascar, and Russia. Some of the largest and most beautiful specimens have been found in Brazil, particularly in the state of Minas Gerais.
In addition to its use in jewelry, Heliodor has some industrial applications as well. It can be used as a source of beryllium, which is used in nuclear reactors and other high-tech applications. However, due to the toxicity of beryllium, precautions must be taken when handling and processing Heliodor.
Heliodor is a complex and beautiful mineral that has both aesthetic and practical uses. Its rarity and unique properties make it a true treasure of the earth.