To raise karat:
Multiply the weight of your karat gold on hand by the raising/reducing factor.
This will give ou the weight of 24kt gold/allow you must add to reach
the correct karat.
Karat Raising Factors (add
gold)
|
|
Karat Wanted
|
Karat on hand
|
10kt
|
14kt
|
18kt
|
0
|
.714282
|
1.39999
|
3.00000
|
10 kt
|
|
0.4
|
1.33333
|
14 kt
|
|
|
.666666
|
Karat reducing factors (add
allow)
|
|
Karat Wanted
|
Karat on hand
|
10 kt
|
14 kt
|
18 kt
|
24 kt
|
1.4
|
0.714383
|
0.333333
|
18 kt
|
0.8
|
0.285714
|
|
14 kt
|
0.4
|
|
|
Karat
|
Gold % by weight
|
Allow % by weight
|
10 kt
|
10/24 = 0.4166
|
14/24 = .5834
|
14 kt
|
14/24 = 0.5833
|
10/24 = 0.4166
|
18 kt
|
18/24 = 0.75
|
6/24 = 0.26
|
http://www.whitegold.co.uk/hardnessofgoldalloys.html:
The following table gives a range of typical "Vickers" hardness values for
fairly common "recipes":-
| Alloy |
Hardness as Cast |
Maximum Annealed Hardness |
| 9 |
70 to 105 |
160 to 170 |
| 14 |
125 to 165 |
150 to 180 |
| 18 |
85 to 125 |
170 to 230 |
| 22 |
70 |
60 to 90 |
| 23.75 |
40 |
70 |
| Silver |
65 |
|
| Platinum SC |
65 |
|
| Platinum HC |
135 |
|
Density of different metals:
|
Specfic Gravity
|
Melting Point degrees F
|
Platinum
|
21.45
|
3214
|
24 kt gold
|
19.32
|
1948
|
18 kt gold
|
15.58
|
1700
|
14 kt gold
|
13.07
|
1615
|
Sterling Silver
|
10.14
|
1640
|
| Metal |
Density |
| Gold |
19.3 |
| Silver |
10.5 |
| Platinum |
21.4 |
| Palladium |
12.0 |
| Copper |
9.0 |
| 9ct |
10.9 to 12.7 |
| 14ct |
12.9 to 14.6 |
| 18ct Yellow |
15.2 to 15.9 |
| 18ct White |
14.7 to 16.9 |
| 22ct |
17.7 to 17.8 |
| Sterling Silver |
10.2 to 10.3 |
| 950 Platinum |
20.1 |
The following tables show the approximate percentages by weight and by
volume of some typical common gold alloys.
| Percentages by Weight |
| Alloy |
Gold |
Silver |
Copper |
Zinc |
Nickel |
Palladium |
| 9 Yellow |
37.5 |
10 |
45 |
7.5 |
- |
- |
| 9 White |
37.8 |
0 |
40 |
10.4 |
11.8 |
- |
| 14 Yellow |
58.5 |
4 |
31.2 |
6.3 |
- |
- |
| 14 White |
58.5 |
0.5 |
27 |
7 |
7 |
- |
| 18 Yellow |
75 |
16 |
9 |
- |
- |
- |
| 18 White |
75 |
4 |
4 |
- |
- |
17 |
| 22 Yellow |
91.7 |
5.5 |
2.8 |
- |
- |
- |
| Percentages by Volume |
| Alloy |
Gold |
Silver |
Copper |
Zinc |
Nickel |
Palladium |
| 9 Yellow |
22 |
11 |
56 |
12 |
- |
- |
| 9 White |
21 |
0 |
48 |
16 |
14 |
- |
| 14 Yellow |
39 |
5 |
45 |
11 |
- |
- |
| 14 White |
39 |
1 |
38 |
12 |
10 |
- |
| 18 Yellow |
61 |
24 |
16 |
- |
- |
- |
| 18 White |
63 |
6 |
7 |
- |
- |
23 |
| 22 Yellow |
84 |
5 |
10 |
- |
- |
- |
Troy system of weights
1 troy ounce
|
31.1025 grams
|
1 pennyweight
|
1.555 grams
|
20 penny weight
|
1 troy ounce
|
5 carats
|
1 gram
|
|
|