INDEX

jewels of real gold color...

The metals and alloys

The precious metals themselves are too soft to use them in pure state, so they are alloyed with other metals to make them hard enough for jewelry applications.

Silver. Usually the alloy called Sterling silver is used, an alloy of 92.5% silver, and the remaining 7,5% copper. The color is virtually not affected, it has the same silvery color as pure silver, but is about twice as hard if worked.
Pure silver is a rather rare metal found free in nature and used since ancient times. Currently it is used for photography and electronics industry besides jewelry. It has a density of 10.5 times that of water and melts at 961°C. 		 

  Gold. There are a few grades for gold content. Commonly silver and copper are mixed to the gold. A carat is the weight content in 24ths of the weight. E.g. 14 carat gold contains 14/24 =~ 58% of its weight is pure gold. Pure gold is 24 carat.
Carat
Content		 Color Remarks
22 Gold yellow Jewelry in mostly Asian countries. Has 'real' gold color. Is soft, but hard enough for most jewelry, if worked properly.
18 Pale Gold yellow Common in many countries, and hard.
14 Pale yellow Common in some countries, in Holland the most popular. Is hard.
8 or 9 Pale yellow For cheap 'gold' jewelry of which is less than half of its weight is gold. 8 carat is sold in Germany and 9 carat in most Anglo-Saxon countries, usually besides 18 or 22 carat.
Not supported by Waarborg Holland
14 or 18 red Pinkish red Red gold: contains mostly copper and virtually no silver as alloying metal. Is very hard.
14 or 18 white Silvery white White gold: contains palladium or platinum as alloying metal. Nickel is not used very much because of allergic reactions of most people to this metal. Is very hard.
Pure gold is a very rare bright yellow metal found free in nature, mainly in South Africa and used since ancient times. Currently it is used for chip and electronics industry besides jewelry. Its value as money standard is getting less important. It has a density of 19.3 times that of water and melts at 1064°C.

Soldering silver heart 2014 Oct 8

Play Here I soldered a silver heart.

Casting Argentium silver

Play Casting Argentium silver, using enriched germanium silver alloy and sterling silver scrap, making the proper composition.

Rolling Copper wire

Play Testing a new rolling mill on rolling a copper ingot to a wire.
  Here an overview of the official hallmark stamps of the Dutch Assay office for silver and gold jewels.

Dutch hallmark stamps


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