Buying Jewellery - Choosing The Proper Metal
Human beings have always enjoyed adorning themselves with interesting objects, so jewellery shopping can be a very fun exciting way to spend your time. But just like most things in life, you will most always get what you pay for. I believe that its important to educate oneself before making these often expensive purchases. Even though people have the option to look up information online regarding jewellery education, I have noticed that there is a lot of conflicting information out there.
Since I’m a goldsmith with 27 plus years of experience, I would like to set the record straight. I will go through several metal choices and the pros and cons of these choices.
What does 14 karat, 18 karat, and 24 karat mean?
I’m always surprised this is not common knowledge, but all it is is a ratio. 14 karat simply means that 14 parts out of 24 parts is gold. The remaining 10 parts is an alloy. So 18 karat is 18 parts pure gold out of 24 parts , and 24 karat gold is pure gold only. Rhodium plating
If you have bought jewellery in a mall box store, you will have heard of rhodium plating. Rhodium is a member of the platinum metals family - of which are - rhodium, palladium, ruthenium, osmium, iridium, and platinum. ("They have similar physical and chemical properties, and tend to occur together in the same mineral deposits"wikipage). This incredibly white metal, while not that hard on its own, is extremely hard when the molecules are layered during the plating process. Plating consists of dipping a ring or other piece of jewellery in a rhodium salts bath, The ring is charged with negative ions, the bath is charged with positive ions, so the rhodium from the salt bath is transferred to the surface of the ring.
I am personally not a big fan of Rhodium plating. It wears off relatively fast. This leaves the consumer with a product that needs constant maintenance, eventually out pricing what a 19k or even platinum ring would have cost. It can cost from $40-$100 to re-plate rhodium plated jewellery..
Why am I telling you this?
I want you all to know why certain rings are less expensive, and thus more enticing to the consumer. You see, I have already told you that the nickel in lower karat white gold makes the gold harder. It is also more brittle, yet much whiter. Nickel is also known as causing possible allergies and skin irritation. The mass producers came up with a plan to market the public white gold jewellery that has very little of the white producing nickel. The new alloy has a much higher percentage of yellow/red copper. The resulting alloy is very yellowish, yet presents much fewer problems with the manufacturing and stone setting processes. The new metal was now very ductile and easy to work.
So how to market this to the consumer?
A thin layer of the rhodium plating was the solution. This turned these rings to ultra white. All of a sudden there was a smaller chance of initial allergies(at least until the warranty wears out). I’m now left to explain this to the hundreds of women who come by my shop. They often complain that their three-month-old engagement ring is “turning yellow” at the bottom - where the rhodium has worn off. I add that the cost of sizing these rings that could have started about $35, is now an added $40 to $100. Now to properly re-size, all of the rhodium must be sanded off, the ring sized, re-polished then re-rhodium plated.
That is all I have to say about Rhodium.
When platinum was first found by the Spaniards in their conquest of South America, They called this white metal they found “little silver” or "platina". They couldn't melt it easily because of it’s high melting point of 32 hundred degrees, so it was virtually discarded
Platinum is found in Russia, Alaska, Columbia, and South Africa.
Platinum is now widely used as the metal of choice in very high end jewellery. The best properties of platinum are it’s natural whiteness, malleability, and it’s durability - it shouldn't crack or wear down over time. I’ve seen platinum rings that are 100 years old and have never been worked on to build up the claws or re-shank. It’s only limitation is the relative softness of it’s surface, which scratches easily and is tough to maintain it's shine. Platinum can be joined with solder to white or yellow gold.
19 karat white gold
Yes there is some nickel in 19 karat white gold, but because the pure gold content is at 80 percent, the nickel has very little effect as an irritant. 19k is so sought out not only for it's incredible durability - but also because of it's natural whiteness, it does not need to be rhodium plated like 14k or 18k white gold. The alloys of 19 karat gold are a trade secret.
Most goldsmiths don’t know the exact combination of metals that yield this very white, easily workable, very durable, and very shiny metal.
Won't crack - solders well.
It is by far my personal favorite.
There are several jewellery brands that now sell an almost exclusively palladium and palladium alloyed jewellery.
It is relatively inexpensive and easy to shine up.
This isn’t the first time palladium was used in jewellery. It’s been used on and off for 40-50 years - since platinum was first taken off the jewellery market for war purposes.
I, as a goldsmith, noticed problems with this metal while soldering or welding. When I first came into contact with it years ago in Vancouver, it was to repair a piece that had separated. I noticed a black soot line inside the weld. Some of the senior goldsmiths said that that was why they didn’t use it; because it oxidised so quickly - even using a good dose of flux.
* Half of the rhodium, platinum, and palladium mined has been used in catalytic converters.
Very malleable, very white, but does not solder well.
It's too soft to use in most serious jewellery construction.
Yet it's very inexpensive and great to have as fun "jewellery", so you don't have to worry as much about losing or damaging it.
Silver also tarnishes without a plating of some sort, although a non-tarnishing silver alloy is now available.
The whitest metal, solders well.
This metal has enjoyed an increasing use in men's wedding bands in recent years. It is very light-weight and non-irritating to the skin. It does scratch easily, but not deeply. Titanium is also relatively inexpensive.
Has to be TIG or Laser welded. Will crack easily at the join. Will not solder to other metals easily.
The word "tungsten" is Swedish for "heavy stone". Thus it is a very heavy, dense material.
It also has an incredibly hard surface. One selling technique is to give the client a file and ask him to try and scratch the surface. Don't drop the ring on a hard surface however, because depending on the alloy, the ring just might shatter upon impact, as it can be very brittle.
Goldsmiths are generally unable to work with Tungsten carbide (as far as I am aware). These rings are made by machining though an industrial process.
No malleability. Grey metal. Won't solder to other metals. Can only be cut with a diamond saw. Must be broken off finger if stuck, using a special set of pliers(hopefully located at your local medical center).
In conclusion, I hope that you have taken something useful from my experience with these metals.