Precious Metals 101 2017-12-13T10:00:27+00:00

Precious Metals 101

Silver, gold, and platinum are precious metals. When pure, they are all too soft for jewelry. They need to be mixed with other metals to make alloys that are more durable or to make other colors.  Silver and platinum are naturally white. All gold is yellow before it is alloyed.

Our company is Robert Hallett, Goldsmith, because we have made more gold jewelry than any other kind and it is the traditional term for the craft. Platinumsmith or Silversmith would also be accurate.

Sterling Silver

Sterling silver is 92.5% silver and 7.5% copper and is marked “Sterling” or “925”. It is slightly less white than pure silver because of the copper. The copper is also the reason sterling tarnishes. In some cases, a bit of tarnish in low areas is part of the beauty of sterling.  Sterling that is regularly worn self-polishes and we can show you ways to prevent or remove tarnish.

Pure Gold

Pure gold is referred to as 24K.  The K stands for karat, not to be confused the weight of gemstones – ct 0r carat.

18 Karat

18K royal yellow (18/24ths gold or 75% gold alloyed with 17% silver and 8% copper and other metals.)  It is a beautiful rich color, easy to work with and durable.  It develops a wonderful patina with wear.  It is marked 18K or 750 (750 parts gold per 1000).

We don’t use 18K alloys in other colors because the 14K versions are better choices.  All 14K gold is marked 14K or occasionally 585.

14 Karat

14K yellow (14/24ths gold with silver and copper).  It is a little less rich and on the pink side of yellow because it has more copper in the alloy to keep a yellow color.

14K White

14K white is alloyed with nickel or palladium to cover the natural yellow gold color.  Nickel white gold can cause an allergic reaction in some sensitive people.  We don’t rhodium plate our jewelry because the alloy we use is naturally white. Palladium white gold is hypo allergenic, but the alloy is on the gray side.

14K Pink or Rose

14K pink or rose gold is alloyed with copper.


We also work in platinum, most commonly alloyed 90% platinum and 10% iridium or ruthenium.  Platinum is a wonderful metal that is mailable enough to set gemstones easily, and has properties of high wear resistance and lack of spring that keeps gemstones more secure than in any other metal.  It is significantly heavier than gold.  Platinum is marked 900, 900pt or 10% IRID PLAT.

In the United States, the precious metal marks must be accompanied by a Registered Trademark. HALLETT 18K in one of our rings indicates that we certify the metal used is 75% gold.

All the metal we use is recycled.  Mining is a messy business.