As per ancient Shastra, Tantraraj-Tantram and Dakshinamurti Sahinta, Shree Yantra made by Gold, Silver and Copper gives enormous benefits of wealth, fame, good health and happiness.

Ratne Hemni Rupye Cha Taamre Drishadi Cha Kramaat, Kritwaa Shreechakra
Nirmaanam Sthaapyet Pujyedapi.
Laxmikaantiyashah Putradhnaarogyadisiddhye

It is mentioned in ancient Shastra Laksha Sagar that Shree Yantra made by Gold, Silver and Copper gives all-around success and prosperity.