Artico Guide to Jewellery Allergies
Allergies and Silver Alloys, Other Alloys, and Pure metals
Artico does have many products that use metals other than silver. Below is a list of metals that can be found in our jewellery.
If you've reached here becasue you think you might have an allergy to Nickel then this blog post will reassure you that Artico has NO Nickel in any of our products. Phew :-)
Here's a summary of what's covered in this blog post:
Bronze (and Brass)
14K Gold (and above)
For the past 80 or so years, nickel has routinely been used as a standard hardener to alloy with softer metals in jewellery and other items. It is also used as an inexpensive plating to increase the shine of silver jewellery.
About 10-20% of people have an allergy to nickel. The number is vague as people with the allergy don’t always know what it is.
A nickel-allergy rash will appear only after the allergy has begun. The rash may subside and disappear but the allergy itself stays with you for the rest of your life.
Nickel has been found in metallic artefacts dating back more than 2,000 years. It was first identified and isolated as an element in 1751. In the 19th century, it came to prominence in plating and in alloys such as “nickel silver” (German silver). Nickel's name comes from the Saxon term 'Kupfernickel' or Devils' Copper. 15th century miners thought the ore looked red-brown like copper but it was too difficult to mine - and they also believed it was poisoning them (actually it was arsenic doing this).
Coins in the USA first used nickel alloyed with copper in 1857. The American “nickel” coin was not pure nickel but in 1881 the Swiss did use pure nickel in their coins.
Also known as “German Silver,” this shiny metal contains no pure silver at all. Its silver colour comes from a combination of nickel, zinc, lead and tin. Artico has no ‘German Silver’ - not only is it not ‘Nickel-Free’ it is not even ‘Lead-Free’.
Most products in Artico are based on silver. All sterling silver will tarnish over time. The speed at which it tarnishes is dependent on the conditions the jewellery has been exposed to. The reasons are many but the main culprit, oxidation, reacts differently on different metals (i.e. on the different alloys used in the silver behave differently) and in different environments.
Rhodium plating protects the silver from the atmosphere but will eventually wear off leaving the silver exposed. The electroplating thickness is typically .75 to 1.0 microns (human hair ranges between 17 to 181 microns (µm = millionths of a meter). Rhodium is itself a precious metal, a member of the platinum family. It has a white, reflective appearance but looks more grey than polished silver. Some of our products are darker than others. If the electric current used in the electroplating process has been set too high the rhodium plating will be darker and at extreme levels, turns black.
Rhodium is a harder substance than silver in its pure form, it’s as brittle as glass, which it is why it’s much less likely to get scratched. Unfortunately this also means it can’t be soldered or remodelled without going through an expensive re-plating process when the alteration is complete.
Rhodium plating is also used on white gold. White gold is actually yellow gold with a white metal coating. The white metal coating is itself an alloy of gold and a white metal - usually nickel, silver, or palladium (another member of the platinum family). The higher the karat weight, the more gold there is in the alloy. It’s the nickel component that generally causes any allergic reaction. Rhodium itself does not contain any allergens such as nickel.
Although 925 Sterling Silver is often nickel-free, it is not always nickel-free. The two main factors are the age of the piece and where it was made.
The 925 number means that 92.5% of the metal is pure silver. The remaining 7.5% is mostly copper and trace elements of some other metal that is used as a hardener. This trace metal may be zinc, tin, boron, lithium, germanium, platinum, indium, or it may be nickel. What the actual blend of the alloy may be depends on where and when the piece was made. Sterling silver made in the South Americas can legitimately have a different composition to the alloy component than Sterling silver originating from say Russia or Europe. When it was made is equally important as even silver originating from the UK from the 18th century will likely have a higher nickel ratio in that last 7.5%.
We cannot be certain that a sterling silver item is 100% nickel free without testing.
Argentium Sterling Silver (935)
Argentium Sterling Silver, also called Argentium Silver or Non-Tarnish Silver, is made of 93.5% pure silver, only a little more than Sterling Silver. It also contains about the same amount of copper, but it also has a small amount of germanium. Germanium acts as a hardener, and has the added benefit of making the silver tarnish-resistant. It is guaranteed to be nickel-free. It is actually whiter and brighter than Platinum and White Gold, and maintains its shine with very little care.
Fine silver (999) is pure silver, 99.9% silver. Fine silver does not tarnish but is soft and therefore not suitable for wearable jewellery. The exception is perhaps some Maltese filigree pieces as this itself involves delicate craftsmanship and is quite clearly a delicate object by design.
Other Metals and Alloys
Pure copper is allergy-safe. Since it is so soft it may however be alloyed with nickel when it’s made into jewellery. Tianguis Jackson maintains their copper elements are not alloyed with nickel. Enamelled or oxidised copper is generally allergen free though be cautious of “antique” plating. Copper does tarnish easily, and can leave green marks on the skin.
Bronze (and Brass)
Bronze is made of copper and tin (Brass is made of copper and zinc). These are nickel-free. Bare metals or oxidised metals are nickel-free.
Modern-day brass is not produced with lead. We avoid “antique” brass, or brass when we don’t know the supplier.
Pewter can be considered the inverse of bronze. Instead of copper with a little tin, it is tin with a little copper. Other minor ingredients may include antimony, bismuth, or silver, but it is certainly nickel-free. Tin is actually classified as a precious metal. Old pewter used to be combined with lead. Modern pewter is not. At Artico we supply only modern pewter.
Surgical Stainless Steel
Surgical Stainless Steel doesn’t seem to cause a reaction in most people even though it can contain 8% to 12% nickel. This nickel is chemically bound to the other metals so it can’t leach out into skin.
Stainless steels were discovered early in the 20th century. Stainless Steel alloys based on nickel have excellent corrosion resistance and high temperature resistance - that is to say... ‘Stainless’. This made these alloys suitable for chemical plants and also allowed the practical realisation of the jet engine. For jewellery however, it’s the ‘stainless’ component that’s attractive!
Titanium is as strong as steel, but as light as aluminium. It does not corrode, does not tarnish, and in its pure state, is totally non-allergenic. It does not react to sunlight, salt-water, or any body chemistry. It can be anodised to be a rainbow of colours.
Grades 1-4 of Titanium are pure titanium. Lower grades (higher numbers) are alloys with other metals. Grade 5 Titanium is called “surgical grade,” and although nickel free, is still an alloy.
Tungsten (Tungsten Carbide) is extremely hard - four times harder than titanium. The only thing that can scratch a tungsten ring is a diamond. Tungsten rings will never bend, nick, or become misshapen.
The binding agents in Tungsten rings can be either Nickel or Cobalt. Cobalt is generally used for lower quality tungsten rings and can be susceptible to scratching, corrosion, and cracking. Some Tungsten rings made with cobalt can react with skin and cause rashes and itchiness. It’s generally avoided and Artico does not carry Tungsten Cobalt rings.
Tungsten Rings can’t be resized. They are typically also 1/2 size larger than traditional metals because the fingers change size during the day, the season, and the gender of the wearer. If they were tight they would become painful when the finger swells due to heat. They have no ‘give’ because they don’t expand in heat.
Parlance and vernacular. There’s a big difference between pure tungsten and tungsten carbide. Pure tungsten is very soft and can be scratched, bent, and damaged very easily. It may seem pedantic but the difference is significant.
Tungsten carbide rings are created by combining tungsten powder with carbon and nickel. The powders are then placed in a high pressure dye to form a blank. To bind the nickel and carbon with the tungsten the blank is fired at nearly 2,000 degrees C. Once the tungsten rings have cooled they are then cut, shaped, and polished. Like Stainless steel, the nickel binder in tungsten carbide is chemically bound during the extreme heat process so can’t leach and cause an allergic reaction.
Even if the base metal is allergen-safe, some plating finishes may not be. Chrome is slang for Chromium, one of the 92 naturally occurring chemical elements. Chrome is a metal, but it is not useful as a solid, pure substance. Things are never made of solid chrome. Rather, when you hear that something is chrome, what is really meant is that there is a thin layer of chrome, a plating of chrome, on the object (the bulk of the object usually being steel, but sometimes aluminium, brass, copper, plastic, or stainless steel).
There are so many complex aspects to Chrome plating (Chrome Plating, Chrome Electroplating, Chrome Dipping, "Chroming - are all the same process, just different names). The detail is not so relevant here but the key facts to be mindful of are:
The process is highly toxic
The compounds used are highly toxic (including the nickel layers)
A chrome piece cannot be soldered
Re-plating is prohibitively expensive (£100s, regardless of size)
Decorative chrome plating is sometimes called nickel-chrome plating because it always involves electroplating nickel onto the object before plating the chrome (it sometimes also involves electroplating copper onto the object before the nickel, too). The nickel plating provides the smoothness, much of the corrosion resistance, and most of the reflectivity. The chrome plating is exceptionally thin, measured in thousandths of a millimetre (25µm).
When you look at a decorative chrome plated surface most of what you are seeing is actually the effect of the nickel plating. The chrome adds a very slightly bluish cast (compared to the slightly yellowish cast of nickel. The chrome also protects the nickel against tarnish, minimises scratching, and assists corrosion resistance. But the point is, without the brilliant levelled nickel undercoating you would not have a reflective, decorative surface.
… this quote lifted from Business Insider from February 2018 - to those who Vape…
“Trapped deep in the aerosol particles that vapers breathe were some of the same toxic metals and metallic elements found in conventional cigarettes, including cadmium and nickel. They also found potentially unsafe levels of several other dangerous substances such as arsenic, chromium, and manganese.”
… and from Dartmouth Toxic Metals:
“Only a small fraction of the population, between 5 and 10 percent, has an allergic skin reaction to chromium. Much like other allergies - to foods, bee stings, cotton, wool - this allergic response is genetically based. When genetically predisposed individuals are exposed to chromium compounds their skin can become reddened and swollen; the condition clears up once exposure stops.”
14 Karat Gold and above
Pure gold is a soft metal and unless it is 24K gold it will be alloyed with something else to harden it and make it more affordable. Hardening elements that are combined with gold can include some combination of silver, zinc, nickel, copper, and palladium. The higher the number 'K', the more pure gold is used in the alloy. Keeping to the range between 14K and 24K gold is safe to wear - unless the customer is allergic to gold itself! All Artico gold embellished jewellery is 14K rolled or filled gold on sterling silver. Yaron pieces for example.
9 Karat Gold
9K Gold contains 9 parts pure gold and 15 parts additional metals such as silver, tin, nickel, zinc, palladium. These ratios are typically expressed as a percentage, the purity therefore of a 9K alloy is 37.5% – this is the proportion of pure gold it contains and items may be marked by the UK assay office as 375. By comparison, 18K gold contains 18 parts pure gold per 24 parts alloy in total. Therefore, its gold purity is 75%.
Depending on the country in which it is sold, 9K gold is not necessarily considered gold! This is true in the US where anything under 10K gold cannot be sold as gold.
As a low-purity gold alloy, 9K gold is harder than 18K gold, it will take longer to wear out. Conversely, this means that a piece made of 18K gold will be relatively easier to scratch, and its parts will bend more easily.
Colour. Compared with 9K pieces, 18K jewellery tends to have a richer colour.
Due to the high proportion of nickel in 9K gold, it’s not recommended for allergy sufferers. Artico has very few 9K gold products and these are clearly labelled.
Artico does not carry any white gold jewellery. White gold gets its colour from alloying pure gold with nickel or palladium. If it is alloyed with palladium it will be safe from allergens. If it’s been alloyed with nickel this may cause an allergic reaction. Since nickel is a white metal and a hardener, it is often the metal of choice to give white gold the ‘white shine’.
An alloy is by definition a combination of metals. Jewellery metals are alloyed for the purpose of achieving a particular colour, or strength, price or malleability, or a combination of all. The choice and recommendation is typically down to the jeweller based on what aspects of the jewellery item the customer is requesting. Even if the alloy does not contain nickel, the presence of moisture from the body in contact with the combined metals can be enough to cause an electrochemical reaction. That reaction can show up on the skin as an itchy, blotchy rash. Even if you are not knowingly allergic to any of the individual metals, you can still be allergic to the alloy.
Niobium is 99.99% pure. It does not react to skin chemistry and will never corrode or tarnish. It is the safest metal for allergy sufferers to wear. It is used for surgical implants. From a jeweller’s point of view Niobium is ideal because it can be easily shaped, is as strong as steel, and has a natural shine. It can be anodised to give a rainbow of colours.
It is a pure element, not combined with any other metal. It does not cause the allergy problems associated with many alloys. Even if people have never been able to wear metal jewellery comfortably, they will be able to wear Niobium.
As of today, the only Niobium jewellery at Artico is from Unique.