Back
Home

Screen Mesh Sizes
As appearing in The Gold Nugget, April 1997
Submitted by Ken Oyler

Last updated: 18 DEC 2004


Mesh refers to the openings between the threads of a screen and is measured by the number of openings per inch; that is, 10 mesh equals 10 holes or openings per inch.

Grain gold is smaller than a troy grain-sized nugget.

Coarse gold will not pass through a 10-mesh screen.

Medium gold will not pass through a 20-mesh screen and averages about 2,000 colors to a troy ounce.

Fine gold will not pass through a 40-mesh screen and averages about 12,000 colors to a troy ounce.

Very Fine gold passes through a 40-mesh screen and averages about 40,000 colors to a troy ounce. Flour gold is even finer than Very Fine gold. It has such a large surface area in proportion to its weight, it usually cannot break the suface tension of water. It tends to float out of pans and over riffles.

Color simply means a tiny particle of gold.

Troy refers to a system of weights in use for precious metals, such as gold and silver, and gems, in which 12 troy ounces equals one troy pound. Troy weights include pennyweights, ounces, and pounds. The ounces and pounds do not equal the avoirdupois weights system, the customary U.S. system, in which other common goods are measured (16 avoirdupois ounces equals 1 avoirdupois pound). For comparison, one troy ounce equals 1.097 avoirdupois ounce.


Back Top Home

© 1997 Gold Prospectors of the Rockies