We are asked this question all the time.
How does jewelry 'turn black' and why is it one of the top concerns of many jewellery wearers?
Let's have a good crack at this issue.
There is a variety of jewellery crafting techniques. Nonetheless the components involved are generally categorized into beads and 'other parts'.
Beads basically last very well although certain types are not colour fast. Others may react badly with chemicals or peel over time.
That said, it is the 'other parts' that are more likely to generate quality issues. And these issues usually arise from the use of metal.
Many metals tarnish. Tarnish is a layer of corrosion that develops over reactive or semi-reactive metals as they undergo oxidation.
Tarnish is somewhat like rust, but with a slower rate of occurrence. It is mainly caused by chemicals in the air and sweat.
Tarnish appears as a gray or black film over the metal. When a piece of jewelery 'turns black', it is a result of tarnish forming on its metal parts.
The photograph on the right shows two ear wires.
The ear wire on the left is new and looks shiny and bright. The one on the right shows how the ear wire will look after months of exposure to air and sweat.
A bad case of tarnish has developed and some say it has 'turned black'.
Often, modestly priced jewelry deal with the problem of metals tarnishing through plating - a thin coat of more inert and attractive looking metal applied to another base metal.
Plating varies widely in materials and quality. One drawback is that they will likely wear off through wear and tear. The good ones can last surprisingly long though.
When the plating wears off, the base metal beneath is thereafter exposed. Base metals may be dark coloured or they may tarnish badly as their protection is gone. Again, in this instance, it has 'turned black'.
A solution in the realm of handcrafted jewelery involves precious metals - usually silver and gold. It's a solution we have adopted as well. Details are explained in lessons 6 and 7.
Working with silver and gold alone will not satisfy us. There are so many varieties of metals and materials out there and they provide us with endless possibilities.
After loads of hard work in research and experimentation, we were able to achieve satisfactory to amazing results with non-precious metals.
There are mainly two issues to tackle:
There are non-precious metals and alloys that are very much chemically inert. We have found a few that are suitable for jewellery crafting. (details in lesson 5)
There are parts and components we have discovered that are of this nature as
well. But there are too few of these to produce a significant range of jewellery
Plated materials are unavoidable. Not that we want to avoid them as they provide possibilities otherwise unachievable.
One wonderful discovery is an amazingly tough plating that offers many colours. The colours are permanent. They do not react to anything we have tormented them with. It seems you will have to scratch the plating with sharp objects or they will last and last.
Not all parts of a jewelry piece are subjected to a lot of friction with bodily parts. An example will be what's below the ear wire of an earring.
It's important for the ear wire to be tough and lasting. Not as critical when it comes to what goes on below it. For such parts, it is still acceptable to use materials less hard-wearing.
First of all, we all sweat differently. Chemical contents in sweat vary so widely among people, the contrast is startling.
We know of people who tarnish their silver jewellery within two hours with their perspiration.
All of us
punish our jewelry differently according to what oozes out from the pores of our
skin. So, along with the sweat and salts from our skin, the air, food and the
various chemicals we routinely come in contact with all contribute to the
encouragement for metals to oxidize.
Jewellery crafters, who choose to work with bright, shiny plated metal parts and wish to offer a higher quality product, often turn to an element known as rhodium.
A rare silvery-white hard metal, rhodium is a member of the platinum group.
Rhodium metal does not normally form an oxide, even when heated. It is the most expensive precious metal. Due to the price factor, it is generally utilized for plating only.
Jewelery parts (we call them findings) plated with rhodium is a lot more expensive.
Brilliant and gorgeous, they have an expensive look as well. Good quality rhodium plating continues to look wonderful even when subjected to harsh, environmental abuse.
All it needs is a little help through occasional wiping and polishing. But here's the caveat - good quality rhodium plating.
Both pendants on the left feature rhodium plated findings.
The one on the left is new and the one on the right has been subjected extensively to tarnish inducing chemicals.
It did not tarnish as easily as cheaper findings would but what happened to it is not normally expected of rhodium, and it was expensive.
We sample every batch of findings we intend to craft into jewellery by testing the specimens intensively under varied conditions to predetermine their ability to resist oxidation and thus tarnishing.
With rhodium plating, we have categorized the different qualities we have encountered into four groups:
What's very confusing and unsatisfying is that there are supposedly guiding factors to the quality of this form of plating:
All the factors above are unreliable. We can never tell if we have purchased a gem or a dud. We can't tell because they all look great, rhodium great.
Putting them through rigorous tests is the only way to see their true colours.
Agalil's quality policy is to use rhodium plated findings of Grade A and B only. This yardstick applies to all other bright and shiny type of plated materials – they must be resistant to oxidation as well as Grade B rhodium plating at the minimum.
As you progress through the lessons, you shall learn about some of the different solutions to combat jewelry tarnishing.
So that you'll have examples to look at, one solution is enameling.
Enamel plating will prevent oxidation as long as the plating is in place. The key is in discovering strong, quality enamel plating.
We have done just that.
Phew! Tough lesson today, huh?
It's quite a bit to take in but it's important when you buy jewelry. Many quality issues lie with the metal components.
How long your jewelry lasts, rests with how well the metal parts resist tarnishing.