WEIGHTS &
EQUIVALENTS
Gold Coated
Many gold-coated aricles
are also used as substitutes for solid karat gold. The thickness of
the coatings are often expressed in millionths of an inch, or
microinches, and the table below provides a way to translate between
these and other measurement units.
|
1 millionth inch
(microinch) |
= |
.0254 micron |
|
1 thousanth inch (mil)
|
= |
25.4 microns |
|
1 millionth meter (micron)
|
= |
39.37 microinches |
|
1 millimeter
|
= |
39.37
mils | |
Following are the definitions of various gold-coated articles
which are sometimes used in place of solid karat gold.
Gold Filled: also called gold overlay, a layer of at least
10-karat gold permanenetly bonded by heat and pressure to one of
more surfaces of a supporting metal, then rolled or drawn to a
prescribed thickness. The karat gold must be at least 1/20 by weight
of the total meta content.
Rolled Gold Plate: Material consisting of a layer of
plating of 10-karat gold or better which is mechanically bonded to a
base metal. The karat gold content may be less than 1/20 but must be
properly identified by weight in terms of total metal content.
Gold Electroplate: A coating of at least 10-karat gold or
gold alloy plated on a base metal by electrolysis. The gold plating
must be at least seven-millionths of an inch thick. Electroplating
is widely used in the electronics and aerospace industries.
Gold Wash or Gold Flash: A film of gold less than
seven-millionths of an inch thick, electroplated on a base
metal.
Vermeil: Sterling silver coated or plated on all
significant surfaces with gold or gold alloy of not less than
10-karat fineness.
Purity
The purity of gold articles may be described in
three ways:
Percent, meaning
parts of gold per 100
Fineness, meaning parts of gold per
1,000
Karat, meaning parts of
gold per 24. Not to be confused with the carat, equaling a fifth
of a gram, which is used to state the weight of a gem stone. The
following table shows the examples of these value for some common
grades of gold.
| Percent Gold |
European System |
Karat
System | |
| 100% |
= |
1000 fine |
= |
24 karat |
| 91.7% |
= |
917 fine |
= |
22 karat |
| 75.0% |
= |
750 fine |
= |
18 karat |
| 58.3% |
= |
583 fine |
= |
14 karat |
| 41.6% |
= |
416 fine |
= |
10
karat* | |
| *The minimum amount of gold that a product
can be composed of and carry the label "gold", according to
the U.S. Federal Trade Commission "Guides to the Jewelry
Industry." |
Weight
The weight of gold or gold articles is usually expressed in troy
ounces. the table below provides a convenient way to translate
between troy ounces and other units of weight.
| 1 troy ounce |
= |
20
pennyweight |
| 1 troy ounce |
= |
1.097 ordinary
ounces |
| 1 troy ounce |
= |
480
grains |
| 1 troy ounce |
= |
31.1
grams |
| 1000 troy ounces |
= |
31.1
kilograms |
| 1 gram |
= |
.03215 troy
ounces |
| 1 kilogram |
= |
32.15 troy
ounces |
| 1 tonne |
= |
32,151 troy
ounces |
| 1 avoirdupois (ordinary)
ounce |
= |
.911 troy
ounces |
| 1 avoirdupois (ordinary)
pound |
= |
14.58 troy
ounces | | | 
