Pureness of Native Gold

In its natural state outside the lode, gold is almost never 100% pure, but instead it also contains some other metals within it. Other metals found in gold are called impurities, not mattering if they are valuable or not. Impurities in gold generally consist in varied amounts of silver, copper and some iron, platinum and cadmium.

The proportion of the contents of the other minerals vary from lode to lode, which makes gold, depending of their origin, have different colors, quality and value in relation to the location from it is extracted. When someone finds gold, be it in its placer or lode shape it is something usual for gold to be assayed so as to state the percentage of impurities it contains, and what are they specifically. The actual content of native gold recently swept from a placer or lode deposit varies from location to location. But in a reasonable average –at least in California- would be 80% of gold and 15% of silver or copper.

Gold that contains 20% or more of silver is called “electrum.” The pieces of placer gold and those that have been eroded from a lode come in a great variety of shapes and sizes; from big pieces- called nuggets- that can reach the very unusual weight of 200 pounds, or the so called “flakes,” the small ones called “grains,” the tiny ones referred to as “dust,” or the microscopic particles that to get a dollar worth one would have to pile up 8 million of these particles. The usual system used to classify the different sizes of gold is done by using the mesh screen. “Mesh” means the number of openings per linear inch of a sieve or a fabric to sift. For example, a sieve labeled with “10-mesh” would have 10 openings per linear inch or 100 openings per square inch. 20-mesh would have 20 openings per linear inch or 400 openings per square inch and so on.