How Do I Know What I am Really Buying? Part 2

Last time we talked a bit about gold and its alloys. This time the topic is silver.

Trivia! Silver was often valued more highly in ancient times than gold because it was less common and more difficult to extract. Gold is naturally found in nugget and crystal form. Silver is sometimes found naturally in conjunction with gold. An alloy of gold and silver, called electrum, was used by 700 BC in coinage, and yes, even the Vikings used electrum.

 Anatolian coins – made of electrum.

The vast majority of solid silver items in the US are made from Sterling Silver. The standard for Sterling Silver in the US is .925, which means that it is 92.5% silver and 7.5% other metals. These metals may include copper, germanium, and other trace metals. The “sterling” stamp is commonly used in the US, but it is also acceptable to use a “925” stamp. Outside of the US the stamp usually says “925”. Like gold, Sterling Silver’s color can vary, depending on exactly what sort of metals are in that 7.5%, but silver is generally valued for its “white shiny” appearance. In fact, the ancient Latin word for silver, Argentum, literally means “shiny”. And that leads us to a specialized form of Sterling Silver.

An increasingly popular form of Sterling Silver is Argentium Silver. This is actually a patented formulation that results in a thin layer of germanium on the surface of the sterling. The germanium layer is tough and resists oxidation- this means that the piece will not tarnish easily. While I know people who work with Argentium, it is still fairly uncommon among small producers, because it is a bit fussy. For instance, you can cool regular Sterling by dunking it in water. If you do that with Argentium silver it will shatter like glass. The Argentium that my metal supplier sells is stamped “935”.

Fine silver is 99.9% pure silver. It is usually stamped “999”, or “999F”. Fine Silver is rarely used for jewelry like rings because of its softness. Many enamelists cast their pieces in fine silver, or use fine silver sheet to enamel on, because it is an excellent base for enameling. The lack of copper in this silver means that there is less danger of the enamels changing color by absorbing the copper. Real glass enamel is colored using metal salts.

Coin silver was a standard in the US for silver coins prior to 1964. This silver is 90% silver, or .90. Coin silver from other countries may vary in silver content.

Terms like Bali Silver, Thai Silver, and Indian Silver have no legal meaning in the US metals market. The item must be stamped with a legal stamp to have meaning. I know merchants who sell Balinese silver that is guaranteed to be 925. And it is all stamped  925.

Company hallmarks can often be used on historic silver pieces to determine the actual type of silver that was used. This is an art in and of itself, and many books have been written on this topic, so I will not be discussing it.

Next Time: Well it looks like silver, but is it?

How Do I Know What I am Really Buying?

WARNING:  If someone tells you something is “gold” or “silver” they may just be talking about the color, and hoping that you will assume it is a precious metal. Real precious metal will be stamped with its purity.

Recently several customers have asked me to explain a bit more about metal and how it is marked in jewelry. They also were wondering what happens to people who lie about the precious metal content of the pieces that they sell.

First let’s talk about precious metal in general. Many different alloys are sold today in the United States, some of which are marketed and copyrighted. The rules for precious metal do vary between countries, and over time, so I will focus on current US rules.

Let’s start with gold. The purity of gold is designated by the term Karats (K) it is a proportion and not a weight. (The term “carat” is a unit of weight that is commonly used for precious stones.) The most common designations for gold are 24K, 22K, 18K, 14K, 12K, and 10K. 24K gold, is considered to be pure gold. It is very rarely used to make jewelry because it is too soft, and will scratch and bend easily. Other metals are added to gold to create an alloy, and this reduces the purity. The added metals may include nickel, zinc, silver, copper and palladium. The color of the final metal and its working properties are the result of the metals that are in the alloy. This is why we have white gold, yellow gold, pink gold, and rose gold, just to name a few. Those terms all refer to the color of the metal, but they do not tell you what the purity of the gold is. Purity is designated completely by the Karat number.

Still confused about Karat weight? Think of it this way. 24K is pure, therefore 12K contains half the amount of gold to other metals that 24K does.

English: Crystaline Gold

English: Crystaline Gold (Photo credit: Wikipedia)

 

 

 

 

 

 

 

I have had several folks ask about  the cost of gold filled items in my shop (more about filled vs plated later). If you are purchasing precious metal jewelry, it is important to know what the “spot price” of metal is. It is also important to know that most jewelers do not pay the spot price for their precious metal.  Spot price is the commodity price that an ounce of precious metal is traded at on the commodity exchange. This price is usually only available for folks who are buying over 100,000 ounces. The vast majority of jewelers purchase their metal from a jewelry supplier, by the ounce. The precious metal starts out as bullion (small bricks). Every time the metal changes hands, or is modified (turned into wire or sheet or casting grain) there is an up charge to cover the labor and equipment and allow for a profit. For example, if the spot price of gold is $1,187.70, which it was this past week, I would be paying about $1237.95 per ounce for casting grain. 24K gold wire, because it requires more processing than casting grain, would cost me $1251.62 per ounce. That is $63.92 more than spot per ounce. And how much is an ounce? Well, my simple gold wedding band is about 1/10 of an ounce. That means that the gold alone, no labor, is worth $125.17.

Next Time: Silver Alloys

All Rulers Are Not Created Equal

Rulers? That doesn’t seem like a very important topic! Well, I have discovered in the last couple of years that all rulers are definitely not created equal. Now in my heart of hearts I knew that there were differences between rulers. Engineers and machinists use more expensive, and more accurate rulers. But one day, when I was in a hurry, I just grabbed a random plastic ruler to measure the link for a chain, and it came back to bite me later. Whether you are drawing out quilt blocks, measuring a pattern for embroidery, or checking the size of a link in a chain, you need accuracy, and consistency.

Most tape measures that we use for sewing are fairly consistent within the tape, but if you have doubts about yours, check it by doubling it back and seeing how well your measurements line up. As you can see in this picture, my tape measurements line up nicely. I always try to buy good tapes for sewing. I got in trouble once by switching between two tapes during a project, and winding up with almost a half inch difference. All of my current tape measures are made in Germany, and even though they are not the same brand, they are consistent. But I still stick with the same tape, just in case.

tape-check

My metal ruler agrees with my white engineers’ ruler, but my little yellow plastic ruler is off by slightly more than 1/16th of an inch over a distance of only four inches.

3-ruler-collage

I was trying to find the plastic ruler that got me in trouble, but I am sure that I threw it away. But I did find one of the kids’ old wooden rulers. This ruler brings up two very important issues. First, some rulers have extra space on the ends, to avoid the problem of wear and tear literally changing the length of the ruler. This is just something to be aware of. But this ruler has another problem. While the inch marks are nice and accurate, the number of divisions within the inch are wrong. Not just off a little, totally wrong. Yes, this is a test…

ruler-end

And just because the inches are good, doesn’t mean the centimeters are. I discovered that my lovely metal ruler, with the very reliable inches, has cut off the beginning of the centimeters, and is off by 1/2 mm. Now that may not be an issue for most people, but if I am cutting a piece of metal, or measuring a link, then my ruler needs to be precise. I simply slide in off the edge of the ruler and use the center to do my measuring.

Now you may ask, how did I get in trouble with an inaccurate ruler? As a production  jeweler, I keep notes about production details. The amount of metal needed for a project, or the size of the rings needed for a particular type of chain. Well, I had notes about a particular chain pattern. And they were wrong. Because the ruler was inaccurate. So, when I went to replicate the pattern. I cut the links the size that the notes said, and they didn’t work, because they are too small. So be aware, all rulers are not created equal.