Precious Metals:Data & Statistics
What Does it Mean?
Also called gold overlay, this describes a manufacturing process in which
a layer of at least 10 karat gold is permanently bonded by heat and pressure
to one or more surfaces of a support metal. Then it's rolled or drawn to
a prescribed thickness. The karat gold must be at least 1/10 by weight of
the total metal content.
With this technique, a layer of 10 karat gold or better is mechanically
bonded to a base metal. The karat gold content may be less than 1/20, but
it must be identified properly by weight in terms of total metal content.
This is a very specific and often misunderstood process in which
gold that is at least 15 microinches thick is bonded to sterling silver
by an electrolytic or mechanical process.
In this process, pure gold is pounded into sheets then applied to other
surfaces by hand. It's usually about 3 microinches thick.
Source: The Gold Institute, Washington, DC; (202) 835-0185, www.goldinstitute.com.
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