PRECIOUS METALS CHEMICAL & COMPOUNDS
AQUA REGIA : A mixture of three parts hydrochloric acid and one part nitric acid used to test the purity of gold and platinum. The mixture is one of the few chemicals that can dissolve those metals.
ROUGE : An abrasive compound used with a buffing wheel to polish metals. Rouge is graded by the size of the abrasive, from very course to very fine (even though none of the grit is as large as any fine sandpaper), and each of the grades in between have different uses. For cutting down a rough surface (or removing heavy oxidation), Brown Rouge (also called Red Rouge) is considered a semi-aggressive primary compound because it contains large grains of abrasive (even though they are so small they can only barely be felt when rubbing the compound between your fingers). Brown Rouge is used for the first step in the polishing process for unfinished metal. Some metal-smiths only use Brown/Red rouge. Green Rouge is finer yet, and is sometimes used for a second polishing. White rouge contains the very finest abrasive and is used for the final polishing to produce a very high shine.
JEWELRY INDUSTRY TABLES, CHARTS AND MEASUREMENTS
Table 1
Fineness of Gold in Karats
United State Markings |
Parts Gold |
Gold % |
European Markings |
24K |
24/24 |
100% |
1000 or 999 |
22K |
22/24 |
91.7% |
916 or 917 |
18K |
18/24 |
175.0% |
750 |
14K |
14/24 |
158.3% |
583 or 585 |
10K |
10/24 |
141.7% |
417 |
Table 2
Conversion Table - Gauge to Inches and Millimeters
Gauge Size |
10 |
12 |
14 |
16 |
18 |
20 |
22 |
24 |
26 |
28 |
30 |
Diameter in inches |
.1019 |
.0808 |
.0641 |
.0403 |
.0508 |
.0320 |
.0253 |
.0201 |
.0159 |
.0125 |
.0100 |
Diameter in mm |
2.588 |
2.05 |
1.63 |
1.29 |
1.02 |
.813 |
.643 |
.511 |
.404 |
.320 |
.254 |
Table 3
Conversion From Troy Weight To Avoirdupois (U.S.) To Metric Weight
TROY (t) |
AVOIRDUPOIS (Av) |
METRIC |
|
Pound (Ib t) |
1 lb t |
0.82291b |
0.3732 kg |
Ounce (oz t) |
12 oz t |
13.16570z |
373.2422 gm |
Pennyweight (dwt) |
240 dwt |
210.6514 dr |
373241.7216 mg |
Grains |
5760 grains |
5760 gr |
Table 4
Alloy Composition of Gold Colors
Color |
Alloy % |
Color |
Alloy % |
Yellow Gold (22k) |
Gold 91.67% |
Deep Green Gold (18K) |
Gold 75% |
White Gold (18k) |
Gold 75% |
Pink Gold (18K) |
Gold 75% |
Green Gold (18k) |
Gold 75% |
Light Green Gold (18K) |
Gold 75% |
Gray-White Gold (18k) |
Gold 75% |
Rose Gold (18K) |
Gold 75% |
Soft Green Gold (18k) |
Gold 75% |
Red Gold (18K) |
Gold 75% |
White Gold (18K) |
Gold 75% |
Blue-White or |
Gold 75% |
Purple Gold |
Gold 80% |
Table 5
Suggested Necklace, Bracelet and Anklet Lengths
Type of Jewelry |
Average Adult |
Length How to Measure for Extra Large or Small Sizes |
Bib Multi-Stranded |
12-13 up to 20"- 23" |
The first strand is usually choker length, and each strand below it longer by approx. 1"-2" |
Collar Multi stranded (all strands same length) |
12"-13" |
Neck Circumference + 1" |
Choker |
14" to 16" |
Neck Circumference + 1.5" to 2.5" |
Princess Length |
17" to 19" |
Adjust to fit customer; usually worn with higher necklines |
Graduated strand |
17" to 19" |
Largest bead in center of necklace, gradually decreasing in size toward clasp. |
Matinee |
20" to 23" |
Adjust to fit customer; usually worn for casual daytime wear |
Eyeglass necklace |
27" |
Adjust to fit customer preference |
Opera |
30" to 35" |
Adjust to fit customer; sometimes doubled to be worn as a choker |
Rope |
40" -45" |
Adjust to fit customer preference |
Lariat Both ends left unattached, or one end with a dangle and the other with a loop |
At least 48" |
Customer preference - no set standard |
Bracelet, Closed Bangle |
Standard: Approx. 6.5 mm ID |
Designed to slip over a slender adult hand; adjust for size by measuring the circumference of the hand at the widest point when hand is held in the position for putting the bangle on, add 10mm. |
Cuff Bracelet, Hinged Bangle |
Standard: Approx. 6 mm ID |
Measure the wrist at the widest point where the cuff will rest, add about 5mm for comfort, unless the wearer wants it snug. |
Anklet |
Sm: 6.5" |
Measure circumference of ankle and add approx. 1/2 inch. |
ADDITIONAL USEFUL TABLES
Recommended Metal Gauge (Thickness)
It is recommended that sterling silver materials should be approximately 10% to 25% thicker than the same materials in14K gold to get comparable strength characteristics.
For |
Use |
Rings and weddings bands |
16 gauge for women's rings |
Bezel material |
32,30,28 gauge |
Ear wires |
22, 20 gauge |
Bracelets |
18, 16, 14 gauge |
Repousse |
24, 22 gauge |
Jump rings |
22, 20, 18 gauge |
Brown & Sharpe Gauge for Thickness in Inches and Millimeters
Gauge |
Inches |
Millimeters |
Gauge |
Inches |
Millimeters |
0 |
.325 |
8.26 |
20 |
.032 |
.812 |
2 |
.257 |
6.54 |
21 |
.028 |
.723 |
4 |
.204 |
5.19 |
22 |
.025 |
.644 |
6 |
.162 |
4.12 |
23 |
.023 |
.573 |
8 |
.128 |
3.26 |
24 |
.020 |
.511 |
10 |
.102 |
2.59 |
25 |
.018 |
.455 |
12 |
.081 |
2.05 |
26 |
.016 |
.405 |
13 |
.072 |
1.83 |
27 |
.014 |
.360 |
14 |
.064 |
1.63 |
28 |
.013 |
.321 |
15 |
.057 |
1.45 |
29 |
.011 |
.286 |
16 |
.051 |
1.29 |
30 |
.010 |
.255 |
18 |
.040 |
1.02 |
32 |
.0080 |
.2019 |
19 |
.036 |
.912 |
34 |
.0063 |
.1600 |
This chart is a relative measure for the workability of different alloys for wire wrapping. Approximately Ultimate Tensile Strength (psi shown in thousands)
14Kt Yellow Gold |
Yellow gold-filled (12/20 & 14/20) |
Sterling Silver |
Fine Silver |
Rich Low Brass |
Pure Copper |
Common Term |
Brown & Sharpe Numbers |
Reduction in Area of wire |
69 |
40 |
40.5 |
26 |
37 |
33 |
Soft (annealed) |
0 |
0% |
88 |
50 |
48.5 |
33 |
49 |
40 |
1/4-hard |
1 |
21% |
98 |
60 |
54 |
41 |
56 |
45 |
1/2-hard |
2 |
37% |
110 |
70 |
60 |
43 |
62 |
50 |
3/4-hard |
3 |
50% |
124 |
75 |
66.5 |
45 |
68 |
55 |
Full hard |
4 |
60% |
145 |
90 |
89 |
51 |
82 |
66 |
Spring hard |
8 |
84% |
Pt. |
FG |
22K |
18K |
14K |
10K |
9K |
FS |
SS |
|
Pt |
1.00 |
0.90 |
0.82 |
0.70 |
0.60 |
0.53 |
0.53 |
0.49 |
0.48 |
FG |
1.11 |
1.00 |
0.91 |
0.78 |
0.67 |
0.59 |
0.58 |
0.54 |
0.54 |
22K |
1.22 |
1.10 |
1.00 |
0.86 |
0.73 |
0.65 |
0.65 |
0.60 |
0.59 |
18K |
1.42 |
1.28 |
1.16 |
1.00 |
0.85 |
0.76 |
0.75 |
0.69 |
0.68 |
14K |
1.66 |
1.50 |
1.36 |
1.17 |
1.00 |
0.89 |
0.88 |
0.81 |
0.80 |
10K |
1.88 |
1.69 |
1.54 |
1.34 |
1.14 |
1.01 |
1.00 |
0.93 |
0.92 |
9K |
1.90 |
1.71 |
1.56 |
1.34 |
1.14 |
1.01 |
1.00 |
0.93 |
0.92 |
FS |
2.04 |
1.84 |
1.68 |
1.44 |
1.23 |
1.09 |
1.08 |
1.00 |
0.99 |
SS |
2.07 |
1.87 |
1.70 |
1.46 |
1.25 |
1.11 |
1.09 |
1.01 |
1.00 |
Precious Metals Comparison Chart
Using Platinum as the Base Standard of 1.00
Abbreviations used in above Chart
Pt |
Platinum |
FG |
Fine Gold |
22K |
22 Karat Gold |
18K |
18 Karat Gold |
14K |
14 Karat Gold |
10K |
10 Karat Gold |
9K |
9 Karat Gold |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Round Wire
Gauge |
Width |
Ft./ln. per Oz |
Oz per Ft |
26 |
.015 |
75.0' |
|
24 |
.020 |
48.0' |
.021 |
22 |
.025 |
31.0' |
.033 |
21 |
.028 |
24.0' |
.042 |
20 |
.032 |
19.0' |
.053 |
18 |
.040 |
12.0' |
.084 |
16 |
.051 |
7.5' |
.133 |
14 |
.064 |
4.66' |
.212 |
12 |
.081 |
3.0' |
.337 |
10 |
.102 |
22.0" |
.536 |
8 |
.128 |
14.5" |
.852 |
6 |
.162 |
9.0" |
1.333 |
4 |
.204 |
5.5" |
2.182 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Half Round Wire
Gauge |
Width |
Ft./ln. per Oz |
Oz per Ft |
24 |
.020 |
96.00' |
.010 |
22 |
.025 |
62.00' |
.016 |
21 |
.028 |
50.00' |
.020 |
20 |
.032 |
38.00' |
.026 |
18 |
.040 |
24.00' |
.042 |
16 |
.051 |
15.00' |
.061 |
14 |
.064 |
9.50' |
.106 |
12 |
.081 |
6.00' |
.168 |
10 |
.102 |
3.75' |
.280 |
8 |
.128 |
2.33' |
.424 |
6 |
.162 |
1.50' |
.667 |
4 |
.204 |
11.0" |
1.090 |
2 |
.257 |
7.0" |
1.714 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Square Wire
Gauge |
Width |
Ft./ln. per Oz |
Oz per Ft |
24 |
.002 |
36.0' |
.028 |
22 |
.025 |
22.0' |
.045 |
21 |
.028 |
20.0' |
.053 |
20 |
.032 |
14.0' |
.071 |
18 |
.040 |
9.5' |
.107 |
16 |
.051 |
7.5' |
.133 |
14 |
.064 |
4.66' |
.212 |
12 |
.081 |
3.00' |
.337 |
10 |
.102 |
22.0" |
.536 |
8 |
.128 |
14.5" |
.852 |
6 |
.162 |
9.0" |
1.333 |
4 |
.204 |
5.5" |
2.182 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Triangle Wire
Size |
Base x Height |
Length per Oz |
Oz per Ft |
1 |
.380" x .225" |
3.75" |
3.160 |
1.5 |
.325" x .200" |
45/8" |
2.590 |
2 |
.258" x .160" |
75/16" |
1.640 |
3 |
.215" x .097" |
l' 3" |
0.796 |
4 |
.175" x .090" |
l' 7" |
0.644 |
5 |
.156" x .111" |
l' 5" |
0.705 |
6 |
.122" x .095" |
l' 11" |
0.519 |
7 |
.103" x .081" |
2' 6" |
0.399 |
8 |
.080" x .064" |
4' 1" |
0.245 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Double Half Round Wire
Gauge |
Height x Width 1/1000" |
Length per Oz |
14 |
.033" x .173" |
3.42 ft. |
12 |
.040" x .162" |
2.77 ft. |
10 |
.051" x .204" |
1.83 ft. |
6 |
.081" x .257" |
10.5 in. |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Sterling Silver Low Dome Wire
Number |
Base x Height 1/1000" |
Length per Oz |
Oz per Foot |
5 |
.170" x .040" |
33.0" |
0.39 |
4 |
.232" x .072" |
13.75" |
0.90 |
3 |
.412" x .062" |
9.50" |
1.15 |
2 |
.515" x .072" |
7.0" |
1.75 |
1 |
.608" x .077" |
6.0" |
2.00 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Gold-Filled Round Wire
Gauge |
Width |
Feet Per Ounce |
18 |
.040 |
13.96 |
20 |
.032 |
21.68 |
21 |
.028 |
28.06 |
22 |
.025 |
35.55 |
24 |
.020 |
56.33 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Gold-Filled Half Round Wire
Gauge |
Width |
Feet Per Ounce |
18 |
.040 |
27.91 |
20 |
.032 |
42.87 |
21 |
.028 |
59.82 |
22 |
.025 |
66.79 |
24 |
.020 |
112.66 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Gold-Filled Square Wire
Gauge |
Width |
Oz/Foot |
Length/Oz |
14 |
.064 |
.232 |
51 3/4" |
16 |
.051 |
.136 |
88" |
18 |
.040 |
.092 |
128" |
20 |
.040 |
.058 |
207" |
21 |
.028 |
.044 |
273" |
22 |
.025 |
.036 |
331" |
24 |
.020 |
.024 |
504" |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Gold-Filled Bezel Wire
Gauge |
Width |
Ounce/Foot |
Inch/Oz |
30 |
1/8" |
.069 |
74" |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Copper Round Wire
Copper wire is relatively in expensive and is usually sold in coils or rolls of a specified length.
Gauge |
Width |
Feet per Pound |
12 |
081 |
50' |
14 |
.064 |
80' |
16 |
.051 |
126' |
18 |
.040 |
199' |
20 |
.032 |
315' |
22 |
.025 |
501' |
24 |
.020 |
793' |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Bronze Square Wire (soft)
Gauge |
Feet Per Pound |
10 |
25.20' |
12 |
40.16' |
14 |
66.14' |
16 |
108.66' |
18 |
169.29' |
20 |
264.57' |
22 |
433.86' |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Bronze Round Wire (soft)
Gauge |
Feet Per Pound |
8 |
20' |
10 |
32' |
12 |
51' |
14 |
84' |
16 |
138' |
18 |
215' |
20 |
336' |
22 |
551' |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Brass Round Wire (soft)
Gauge |
Feet Per Pound |
8ga |
20' |
10ga |
32' |
12ga |
51' |
14ga |
84' |
16ga |
138' |
18ga |
215' |
20ga |
336' |
22ga |
551' |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Brass Square Wire (soft)
Gauge |
Feet Per Pound |
10 |
25.20 |
12 |
40.16 |
14 |
66.14 |
16 |
108.66 |
18 |
169.29 |
20 |
264.57 |
21 |
395.00 |
22 |
433.86 |
24 |
750.00 |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Nickel Silver Round Wire (soft)
Gauge |
Feet Per Pound |
8 |
20' |
10 |
32' |
12 |
51' |
14 |
84' |
16 |
138' |
18 |
215' |
20 |
336' |
22 |
551' |
WIRE LENGTH PER OUNCE and WEIGHT PER FOOT - Nickel Silver Square Wire (soft)
Gauge |
Feet Per Pound |
10 |
25.20' |
12 |
40.16' |
14 |
66.14' |
16 |
108.66' |
18 |
169.29' |
20 |
264.57' |
22 |
433.86' |
No matter how you shape it, wire sculpted jewelry is here to stay. The more you know about your medium of choice, wire, the better your work will become.