KNOW THE METALS

Brittleness is the opposite of ductility. A metal is called brittle if it breaks easily or suddenly when being drawn into a wire. Elasticity is the capability of a metal to return to its original form after it has been worked on.

Fusibility is the capability that permits one metal to be combined with another metal, both in the sense of being mixed together in a molten form and in the sense of two metals being bonded (fused or welded together.

Malleability, ductility, tensile strength, and fusibility are desirable characteristics, since metals with these characteristics can be easily worked and will hold and retain their shapes after working and wearing. Metals that are brittle and elastic, with little fusibility, are undesirable for jewelry because they will break or lose their shapes and they cannot be used in combination with other metals. All precious metals are malleable, ductile, tensile, and fusible.

An alloy is a combination of two or more metals, in which the metals are combined in molten form, like mixing the ingredients of a cake. The reasons why a precious metal may be alloyed with a base metal will be explained under the individual metals, but the general reasons have to do with the above characteristics. A metal that is too malleable may be combined with another metal in order that the resulting metal will be harder and more durable, while retaining its own unique characteristics. On the other hand, a metal that is too hard may be alloyed with another metal to make it softer and easier to work, again while retaining its own unique characteristics.