The ultimate crash course in metal jewelry components and chains! I taught this at the Permanent Jewelry Expo (PJX0 in Las Vegas) and now you can watch it here.
This basic knowledge is essential for anyone new to jewelry making, but also informative for seasoned goldsmiths. The course will cover different metals and styles popular to PJ, and those that should be avoided; measurements and the gauges of wire and jump rings best for PJ; the difference in the performance, durability, pricing, manufacturing process, reactivity and allergies for each metal; how to test for fake metals; how to clean permanent jewelry. The goal of this course is to educate you so you can educate customers.
Imperial vs Metric
Foot/inches/gauge vs Meter/centimeter/millimeter
1m = 3.28ft = 39.37” = 100cm = 1000mm
Average Lengths for Jewelry
Over the counter jewelry (for women)
- Bracelet 6.5” (including clasp) +1” extension
- Short Necklace 16” (including clasp) + 2” extension
- Anklet 9” (including clasp) + 1” extension
Average Lengths for Permanent Jewelry (note that it varies by region)
- Average Women’s Bracelet 6.5”
- Average Men’s Bracelet 7.5”
- Anklet 10” (varies widely based on comfort)
Thickness
Imperial – Gauge (ga) vs Metric – Millimeters (mm)
(It’s very confusing because many places will refer to wire in gauge and jump ring diameter in mm. The worst thing is that the higher the gauge number, the thinner it is. Here’s a quick chart.)
Diameters – inner and outer
Most companies will specify if it is inner or outer with ID and OD
Most Popular Jump Ring Size for Welding(photo of a delicate chain kit)
- 24ga and 22ga (1 weld at 7w)
- Most popular is 3mm OD (2.0mm ID)
Popular Metals for Jewelry (solid gold, rose gold, gold filled, gold vermeil, gold/silver plated, 925 silver, stainless steel)
Metal Not Suitable for PJ
First – chains that are not suitable for permanent jewelry so we can just eliminate it from further discussion
- Plated Metal
Popular in costume and cheaper jewelry, brass, copper and pewter are plated gold or silver. However, the plating tends to last 1-4 months. While it works for traditional jewelry that you can take off after a day or so, it’s not meant to worn constantly. The plating comes off and there’s nothing you can do to clean it to its original luster. Many suppliers call gold plated gold filled, it’s not just China, it’s Europe as well.
- Silver Plated with Gold
It is better, but the gold will eventually come off and the silver is exposed. This is still a popular thing because you can have nice casted charms and connectors that you cannot get with gold filled. I’ll talk a bit more about why later
- Stainless Steel, Surgical Steel and Nickel
Although it doesn’t tarnish like silver, brass or copper, a lot of people are allergic to it. Stainless steel has nickel in it. Surgical is more corrosion resistant than stainless steel, but it has nickel. Nickel is the major cause of allergic reactions
Solid Gold
- 24K is pure gold
- Popular are 22K, 18K, 14K, 10K
- Example: 14K means that it has 14/24= 58.3% of the metal’s mass is solid gold (rest is alloy)
- Rose Gold has higher concentration of copper in the alloy
- White Gold has higher concentration of silver, zinc or palladium
925 Silver (Sterling Silver)
- 92.5% silver, 7.5% alloy (usually copper)
- Tarnishing (silver used to be used as a tool to test for poison in drinks and food because it turns black when it comes into contact with certain chemicals, such as arsenic and sulphur. It tarnishes with chlorine and a few other chemicals. However, it can be easily cleaned).
- Anti-Tarnish Coating (E-coat and Agere)
- Allergies (there are people who are allergic to silver, but fewer than those who are allergic to nickel and rhodium. When jewelry is labeled hypo-allergenic, they mean that there is no nickel in it).
Gold Filled
- Strange Name – It was developed in the 1930’s as a way to make jewelry as durable as solid gold, but at a price that is more accessible. It seems like a misnomer because it is not filled with gold. They first had solid gold tubes filled with brass. Eventually the word gold filled with brass has been shortened to gold filled
Gold filled wire
- Gold filled wire is the basic component for all gold filled chains and jump rings. It is made with a gold overlay and a brass core. True gold filled wire is only made in the USA, where they then ship to chain factories in the USA or countries to be machined into chains.
Gold filled sheet
- Gold filled sheet is made with an outer sheet of karat gold, with a brass core. As with gold filled wire, it is only made in the USA, and only by one company. There is single clad (which means that it is single sided) and double clad (which means gold is on both sides with a brass core, like a sandwich)
- Single Clad (single sided)
- Double Clad (two sided)
- Denotation (Quality Stamp)
Example: 14K gold filled is denoted as 14/20 GF, or 1/20 14K GF
Gold filled MUST have 2 things
- Gold Content needs to be at least 5% gold in the karat specified
- Example: 14K gold filled would be 1/20 of 14/24 = 0.05x = 0.029 (or 2.9% solid gold) the whole thing melted down, there would be 2.9% solid gold.
- Assay Test – Lab test (only a refining lab can test for this and it generally costs about $150 per sample)
- FTC states tolerance of 10% (so, must have 2.61% gold for 14/20 GF)
- The karat gold content must be on the OUTSIDE (it can’t just be 5% of some karat gold, which would be much easier to manufacture than gold filled)
- Acid Scratch Test You can test for this using an Acid Scratch test
- You can buy kits for about $ 40 to test the outside of the gold filled pieces.
- You rub the sample piece onto an abrasive scratching stone.
- The metal leaves traces on the stone.
- You drop the acid onto it.
- When it is plated, there is not enough gold to that gets rubbed onto the scratch stone and when the acid is applied, you will see the gold disappear
- In the kit you have range of popular karat testing acids.
Ask Pointed Question! (when you are asking a potential supplier if something is gold filled, ask very specifically “Is it 1/20 14k? Is there 2.9% solid gold if I sent it to a lab to test?” I have asked is something gold filled? They say yes, but I see their machinery in the back and it doesn’t look right. There are plating racks and tanks. Ok, gold filled sometimes you plate to cover the solder marks in the chains or sometimes people want to specific shine, like Hamilton finish is the most popular that you see. They say yes, it is gold filled, they guarantee excellent quality…until you ask very specific questions on assay test and gold content. Then it is a very heavy triple plating that is guaranteed for six months.)
Durability of Gold Filled
- 100x more gold > gold plated (There is at least 100x the amount of gold in gold filled as there is in plated gold
- Lifetime product (for normal wear and tear it performs exactly like solid gold)
- Welding (there will be a dark mark, the size smaller than a poppyseed, where the brass has been exposed during the welding process, and it darkens with time. Most people don’t mind and you can see if on my chains that I’ve had on for over 9 months. However, if it bothers you, then you can use solid gold jump ring and that mark will not be there)
Allergies to Gold Filled
- Allergies to solid gold = will be allergies to gold filled (customers usually know if they’re allergic to karat gold, there are some who are allergic to solid 24k gold)
- Brass allergy (some people have a brass allergy or something in their skin pH that reacts to the brass inside that makes everything dark. It’s rare, but it has known to happen. Our manager has this and she is wearing gold filled and can show you).
Chains Stretching
- All delicate chains will stretch – if you pull hard enough those that won’t are going to be very thick. So, it is a matter of how hard it’s being pulled – if it gets caught on something. Or if it will stretch with normal wear – then you don’t want to use that.
- Anklets (tend to stretch more than bracelets due to the flex of the tendons. Incidentally, it stretches less if the chain is below the ankle bone. It’s counterintuitive, but I’ve done an experiment welding many different lengths of the same type of chain on myself)
- Best to ask the supplier
- Rule of thumb
- Delicate AND airy = will stretch (if the wire is fine, better to go with tighter weave – the shape of the links matter)
- Hammered resists stretching > than round (of the same shape of link and thickness of wire)
