I am very sorry that the previous post of Arany was deleted because it was in Spanish.
He mentioned something very interesting. The way native americans of the Andes processed Platinum.
I don't know if you knew, but Platinum was a metal discovered by the ancient Andean peoples, and the discovery was carried to Europe by the Spaniards. Now, Platinum has a very high point of fusion which was beyond the heat provided by the tech the natives knew. However, they lowered the melting point by processing it in the form of alloys.
Natives produced platinum jewerly!
I recall Arany mentioned the method in Spanish with precision!!! A method I have been finding out for a long time. Now is gone
Pinguin