Rivaled the price of gold and was used on the most important figures eg the Virgin Mary - until a reward was offered for a synthetic version - https://www.artsy

Rivaled the price of gold and was used on the most important figures eg the Virgin Mary - until a reward was offered for a synthetic version - https://www.artsy.net/article/artsy-editorial-a-brief-history-of-blue https://www.artsy.net/article/artsy-editorial-a-brief-histor...