Alexandrite is one of the most rare coloured gemstones in the world. It is the colour change variety of the mineral group Chrysoberyl. Its origin dates back to Imperial Russia where the gemstone, after being discovered in the Ural Mountain regions, was named after Tsar Alexander II. Alexandrite can only form when aluminium and beryllium combine with trace elements such as titanium, iron and most importantly chromium. This contributes to its rarity as many elements need to be present in the correct conditions in order for Alexandrite to form.