posted 01-02-2004 10:43 AM            

Hello all,

I was wondering if someone could help me with a problem I've had for some time. I purchase silver testing acid, buffing wheels etc., from a jewelry supply house in Toledo OH. My question concerns the testing acid.

When I put a drop of acid on a known sterling item it simply turns the item a dull grey. The label says it contains muratic acid and nitric acid. Some other acid that I have used (ProCraft) indicated on the packaging that a "bright red" reaction was sterling. However, when this is applied to a known sterling item it turns dull grey with a HINT of red on the edges. When I use gold testing acid on known silverplate, this sometimes turns green, sometimes does not. This is a BIG problem with old silverplate (or some other metals) which turn the acid kind of dark grey or black (no green).

My question is, where can I get acid which DEFINITIVELY indicates that the item is silver.

posted 01-03-2004 07:11 PM            

Generally, almost all the silver one will encounter in collecting is marked in some way. Experience can guide you in evaluating unmarked items once you have familiarized yourself with marked ones. For example, the larger an item is the less likely it is to be sterling and the more likely it is to be some sort of plate.

The concept of the acid test is usually that it will react to the copper in the sterling. The various grades of color, the tones, show what percentage is copper and by inference what the content should be called. The problem here is that frequently old silversmiths did not cooperate with us by using standard grades and fixed percentages. They used what they had on hand. This causes us endless problems as some things that should be at least 90% silver are frequently other quantities. Acid tests might be useful if all you are doing is buying to melt, but even then they are dubious.

I am not as down on buffing wheels as some here. They have a place in silver work. But remember they can be very dangerous, require a lot of experience and give silver a new look. They are not something to just start playing with. Try to find an experienced buffer for some elementary instruction before using.

posted 01-04-2004 03:07 PM            

quote:

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Experience can guide you in evaluating unmarked items once you have familiarized yourself with marked ones.

---

I will echo what Dale and swarter have said. Experience is best.

But before we even get to asking the question about metal content, there may be a better question.

• Does it really matter if the item is sterling, coin or other?

Since your medallion napkin rings are solid there is an noninvasive test you can use. It is called the Specific Gravity Test. It is not hard to do but it does require an accurate scientific scale, distilled water, an accurate thermometer and some other general lab equipment. Lastly, although this test is a bit cumbersome to set up it is not hard to do but it does take some experience to get accurate results.

I would not worry about testing things and just judge an item based on your experience and on what will be important to your customers. For example this weekend June and I saw some things we would have purchased except for the fact that they were unnecessarily invasively tested. After testing with acids the silver plate was damaged. We rarely buy damaged or overly polished items.

You may need to educate your customers. I know several dealers who do a good job of educating their customers in the process have found that respect for an items history is often the best way to increase an items value.

posted 01-04-2004 03:10 PM            

Medallion silver is something that can frequently be identified by the figure on the medallion. There has been a great deal of research which now lets us assign makers based on the figure used. These sound like a wonderful find. Usually old napkin rings do not come in sets except when they do come in sets. Please post a photo: they sound wonderful.

My own personal idiosyncratic rule of thumb FWIW: US sterling is always marked; US plate is always marked: when a US piece is not marked I begin to suspect it is coin silver. Which means reference books.

posted 01-05-2004 12:40 AM            

The reality of my business was that I bought in quantities. Usually everything was a filthy mess. Since I was running between 200 and 500 pieces a week this way, and had to get them into the stream of commerce, I needed to polish quickly and well. Which meant I learned to use wheels. Frequently only after buffing and polishing did I realize that the item was Georgian or early coin. The buyer never objected to the polish job.

On the metal content, there are a large number of buyers who will prefer an ugly piece of sterling over a lovely piece of plate. Never have understood this, but there are loads of buyers for whom the metal content is definitive. So, yes, for many dealers content is all important. Because their customers have been taught to prefer things that way.

posted 01-05-2004 08:23 AM            

Sure in a skilled hand buffing can work wonders. But it takes a lot of experience to achieve that skill. The realities of being a sole proprietor handling 200-500 old very dirty pieces a week will make using a buffing wheel on some or all seem to be the best use of ones time.

Search back through the forums posts and you will find that patina is an very desirable feature. It takes years and years of hand handling to achieve the desired patina. Evaluation of patina can provide all sorts of insights about a piece. Once the patina is gone so are those insights. Even with the lightest of touches the using of a buffing wheel will destroy or significantly change the patina forever.

I do understand that if your business is going to be successful then you have to do what makes you money: buy low, sell high, turn over inventory quickly, have repeat customers, etc. We have traveled around the country and recognize that dealers must also face the regional realities of customer preferences. It seems to me that the further south and west of Louisiana the greater the need for a mirror shine. I spent several years living in big hair country (just kidding - heck my mother is from Texas) and California where big, shinney, new is predilection of many. So to remain in business a dealer must provide a product that their marketplace will buy. I am not going to be a good customer.

I suppose that if the business is pattern matching/replacements then your customers aren't looking for antiques, they want something new or near new. As such then wheel buffing 200-500 pieces a week makes sense. If on the other hand you are selling antiques it doesn't. It takes careful inspection of antique silver and a lot of experience to determine which method of cleaning might be best for a particular item of interest. When dealing with antiques, only one cleaning/polishing method does not fit all. Even if you only use the wheel, there are many different types of rouges, pads (wheels), speeds and technics to be employed and to be mastered. Use the wrong combination and you can forever alter or damage an item.

I don't know if we "antiquers" will ever be comfortable with the idea of buffing. My hope is that the pattern matching/replacements dealers will take the time to learn how to inspect dirty old silver and then set aside what might be best saved from the buffing wheel.

posted 01-06-2004 12:13 AM            

In my experience, having known dozens of silver dealers over both long periods of time and large areas of the US, I would say that all silver dealers use buffing and polishing. Not all the time, but when needed. I have never known anyone who refused to buff silver. Most simply won't admit to it. But then, most of my experience has been in Central and Mountain time zones, with quite a few Pacific time zone dealers thrown in. I really don't know much about New England standards.

I can on a good day, do between 20 and 50 pieces of flatware an hour. That's how I got it done.

posted 01-15-2004 01:41 PM            

If these were mine, here is what I would do. Put them away and enjoy them. When I had enough really nice silver I would set off to do shows, flea markets whatever. Would head west to I55. Then south on 55 to I40. West again to Little Rock. Or a short jog east into Memphis. Here is where silver country begins IMHO.

The difference in silver buyers is like night and day. In this area there are wonderful customers. Lovely people. Knowlegable, polite, refined. People who know and love silver.

Continuing to the southwest: Dallas, Houston, Austin, San Antonio, Fort Worth, Tulsa, Oklahoma City. All of them have knowlegable silver buyers. At least one of whom would recognize your napkin rings and be ready to pay for them. Medallions are fairly well known, have many collectors and should have a ready market. But that may be just me. I am totally burned out on midwestern silver buyers.

There is one possibility overlooked here. The medallions themselves may be sterling/coin applied to a plated ring.

posted 01-16-2004 06:04 PM            

Looking back, I can recall dozens of instances where someone in my booth would suddenly realize that the pieces were plated. Suddenly, they would scream out something about 'trash' and 'deception'. Then forcefully throw the silver onto the concrete floor. Had this happen once with a really great piece of Pairpoint.

posted 01-23-2004 10:54 PM              

Best wishes,

posted 01-24-2004 02:45 AM            

As for your specific napkin ring question, I am not sure the answer. Often, solid silver napkin rings are more flexible than plated examples because the latter are made of some kind of thick base metal. Also, the lack of marks does not necessarily mean they are plated. Of the mid-Victorian napkin sterling/coin rings I have handled, I bet at least half were unmarked, or only had a factory number. I do not know why so many napkin rings were not marked with silver content or maker's names. If you can see the solder line, that could be a sign of being silver. Since plated examples would be plated after the ring was soldered together, the plating would most likely cover the seam. Perhaps somebody who has handled more silverplated napkin rings than I can tell us if the solder seam shows through the plate?

Your rings date c. 1865-1870.

Sue, in response to your questions:
The best tool for determining silver is experience. After a while, you will be able to intuit whether an item is silver based on its flexibility, feel, etc. If you (or anyone) is planning an acid test, do not file notches in the silver or put the acid directly on the item. Both are invasive and damaging.

I have had one occasion to test an item for silver content. I sold an item on eBay as solid silver (in fact, an unmarked 1870s napkin ring). The buyer disputed my claim, and asked me to test it. So I rubbed the bottom edge of the napkin ring against the touchstone until I had a sufficient deposit, on which I dropped the acid. This was not overly invasive. It just left a barely visible scuff on the bottom edge of the napkin ring. (And it was silver).

Some metals are not magnetic. This includes silver. If an item is attracted to a magnet, it is not silver.

posted 01-24-2004 03:59 PM              

Thanks for the helpful information. I think I will stick with the magnet test, as it is non-invasive and not likely to damage any of my collection.

Best wishes,

posted 04-20-2004 10:27 PM            

Here may be the easiest ways to measure density without lab volume measuring equipment.

Method #1: First, weigh the coin. Then, fill a small container (diameter just larger than the coin, height significantly greater than coin width) to the brim with water (use an eye dropper to place in the last few drops to get a repeatable volume, fill to the overflow). Now weigh a piece of dry paper towel, place it under the container, quadruple folded, and gently place the coin in the container without agitation (use tweezers), causing the water to overflow onto the towel. There should be no air bubbles clinging to the coin. Use a piece of the towel to soak up any overflow drops left on the outside of the container. Reweigh the wet towel. The difference between the dry and wet towel weight is the weight of the displaced water, which is converted to volume using 1 gram per cc or ml (you can temperature correct this, but the difference will likely be less than the precision of your scale and lab technique). Divide this volume into the coin weight (mass, for purists), to get the density, and compare to that of pure gold. The less pure the gold, the lower your calculated density will be to that of pure gold. The problem with this technique is that you tend to slosh more water out of the container than is equivalent to the coin volume, giving a lower density result than is fact.

Method #2: More math, less lab technique, no need to ease the coin without sloshing. Just add water with dropper to overflow in both cases, with and without coin, don't bother caring about what happens to the overflow (except don't leave it on the container exterior or on the scale). Separately weigh the coin, the container full of water without the coin, and the container full of water with the coin. The density of the coin will then be the quantity of the weight of the coin times the density of water (simply 1g/cc in cgs system), divided by the quantity of the weight of the coin plus the weight of the full container without the coin minus the weight of the full container with the coin.

Coin Density = (Wt. Coin x 1g/cc) / (Wt. Coin + Wt. Full Container W/O Coin - Wt. Full Container With Coin)

Here are some densities I found, in grams per cc (or ml):

Metal Density
Gold 19.3
Silver 10.5
Platinum 21.4
Palladium 12.0
Copper 9.0
9ct Gold 10.9 to 12.7
14ct Gold 12.9 to 14.6
18ct Gold Yellow 15.2 to 15.9
18ct Gold White 14.7 to 16.9
22ct Gold 17.7 to 17.8
Sterling Silver 10.2 to 10.3
950 Platinum 20.1