4th - Blue Topaz

Topaz is a gemstone that can be found in various colours and hues, and blue topaz was once considered the rarest. However, a permanent treatment known as diffusion, where colourless topaz is heated with an element like beryllium coating, can transform it into a light blue shade. The treatment is permanent, and deeper blue hues like "London blue" and "Swiss blue" are obtained through irradiation and heating, also considered permanent. Blue topaz is a resilient gemstone that looks stunning in a variety of jewellery styles, including earrings, pendants, bracelets, and rings. It has been historically linked to love and affection, making it a perfect gift for an anniversary.