Goldstone is often mistaken as a natural gemstone. It is, rather, a glass with copper flecks in it. Goldstone was created accidentally in the European Renaissance period, when alchemists were trying to create gold.
Goldstone was originally made by monks in Italy, and due to this association with monastery, it is often used in religious jewelry.
For making Goldstone, copper salts are added to brown colored liquid glass in low oxygen atmosphere. As the glass cools, salts turn into copper crystals.
It is abundantly available in reddish goldstone and dark blue goldstone, but there is a relatively less available green goldstone as well.
Goldstone is said to promote calmness and stability.
My nature inspired Goldstone jewelry collection is available for sale at ETSY.