Amethyst Kate Stone White Gold Jewellery Ring.

Amethyst Kate Stone White Gold Jewellery Ring.

 

By Stone.

In the 19th century, the color of amethyst was attributed to the presence of manganese. However, since it can be greatly altered and even discharged by heat, the color was believed by some authorities to be from an organic source. Ferric thiocyanate has been suggested, and sulfur was said to have been detected in the mineral.