In modern times, karat gold is strictly followed science to create 21st century standards of purity to produce testable 10Kt, 14Kt, 18Kt, 20kt gold and sterling silver. For example, 14kt gold is 58.5% pure gold, and 41.5% other alloys. These other alloys affect the final product color and behavior in predictable ways, when standard mixing (alloying) practices are followed.
BUT, a customer walked into our store with a 1/10oz gold coin, an 18kt yellow gold men's ring, and a fine silver ten dollar coin...and asked us to "make him a rustic neck chain." With this mixture? "Yes!" Cool! Let's do it. It made a mostly silver tone metal, with hints of yellow, that was very malleable, formable and more than likely more tarnish resistant than standard sterling silver.
We melted it into a cohesive lump, then drew it out into wire. Formed the wire into rings and separated them all. Then ovaled them all, linked together. Soldered them all. Doubled the thickness on the end links and handmade the clasp.
It's a one of a kind chain made of a unique proportion of precious metals, that is wearable- rather than old coins laying around getting dusty. Thank you for the amazing project- it was grueling, thoughtful and adventurous!