Interesting Antique Silver Pear..Its Purpose??

[bubba]

While pure silver has a specific gravity of 10.46, silver that is not pure like coin will be alloyed with other unknown metal/metals. Therefor the specific gravity will be different, depending on the type of alloy/alloys used. Acid testing will reveal the presence of silver with great accuracy when done by a well skilled assayer. Should you not use both tests in conjunction to obtain the most accurate results?

[larrywseale]

Very true Bubba BUT!

While I can't give you the exact alloy without a fire assay or XRF analysis, I can come up with a pretty good educated guess. It's interesting to note that "pure" silver & molybdenum are the only two common metals with a specific gravity in the 10's which narrows the field tremendously.

I'm not a metallurgist but the common coin alloy is 89.9999% silver & 9.9999% copper (specific gravity 8.96) with a minute trace of whatever impurity was in the metals before mixing. US coin silver has a specific gravity of 10.31 & I suspect that even older foreign coin is in the same range because silver/copper is by far the most common alloy . The few unmarked pieces are generally pretty old so that also helps.

I have nitric & sulphuric acids & potassium dichormate salts so I can acid test if absolutely forced to but acid testing is also educated guessing unless it's something simple like plate or not. I certainly use it to test scrap but typically not finished pieces where I have to mar a piece unless I can do it inconspicuously.

Sigh! If only I could justify (and could solve the bigger problem - lack of money!) buying a XRF analyzer, the question would be moot.

[larrywseale]

My disclaimer,

My scant knowledge of smithing is limited to US & perhaps a touch of Native American produced items.

[larrywseale]

Should you not use both tests in conjunction to obtain the most accurate results?

I got long winded & didn't give a specific answer. I agree with you if it's practical but there is no way to do so without some damage to the piece you're testing.

If I test silver with nitric acid, all I can hope for is cream or green and if I mix a "silver test" solution, then I have to have reference samples to try & color match shades from bright red through brown. Done correctly, I think hydrostatic weighing is more accurate but both methods have room for error.

[bubba]

When metal is alloyed with undetermined alloys the specific gravity is altered. The specific gravity of silver 10.46 can be achieved by alloying lead, tin and antimony as shown in the chart below. When acid is applied to the surface of silver and it's usual alloys it simply leaves a mark which can readily be polished away with little effect especially on flatware which was polished regularly during its use. It is not a greatly destructive test if done properly. It would readily indicate the lack of silver content in the alloys in the chart even though the specific gravity would indicate silver content. This is why I asked question about the use of both tests to provide the best results. I would guess the acid provides the more conclusive results but the spec grav would not harm the item and should be performed first.

[larrywseale]

Bubba:

Not worth arguing about. I can come up with an infinite number of combinations from the periodic table that have specific gravity in the 10's but I prefer to deal with what is not what could be.

As far as acid testing without damage - as has been pointed out, putting a drop of acid on a heavily plated surface only tells you what the surface is. Scratches & file marks are a lot harder to buff out.

That said, I agree that acid testing is an important tool as are magnets, "ring" testing, fire assay, xrf, hardness, common sense, etc, etc. I'm certainly not going to test a proof bullion coin with acid or by melting but counterfeits exist as do hollowed & filled silver/gold bars and other fakes designed to separate you from your money. I don't use a screwdriver to try & remove a nut nor do I use a file on an antique "silver" piece. That was my point.

[zilverik]

Hi,

Apart from the very interesting discussion about unmarked silver, there is still the original question left. The question was: What was the purpose of this object? In my opinion the purpose was to bring light. See my object (and question): http://www.925-1000.com/forum/viewtopic.php?f=8&t=25269" onclick="window.open(this.href);return false; This chamberstick has the same purpose. There is room for a fuse and there is an opening for the fuse to light it.

Regards,

Zilverik

[Zolotnik]

Hi all -
the object is an electic bell button, with the electric wire (the opening above) and the push button (the opening on the underside) and the contacts missing - in the classic form of a pear. It used to hang from the lamp over the table in the dining - so you could ring for the servants. About 19oo-20 in use in better homes. Even Fabergé in Russia made some - though in enamel....

Regards
Zolotnik

[dragonflywink]

Maybe I'm missing something in the pictures and the owner's description - but there doesn't seem to be any openings for either a wick/wax cord or for wiring? Just a threaded post on one piece and a matching threaded socket on the other.

~Cheryl

[Zolotnik]

Hi all -

for those who did not get it:
In Europe quite often used in the better homes...it was hanging over the table (from the lamp) on its wire (the wire was used to electify the contacts), the bell was normaly in the kitchen to inform the servants that their service was expected. It is a bell button in pear form - no bell!
In this example from Sweden, solid silver S830, the electric wire is missing!!!!!!!!!! The holes you see are for the wire!













Here you can see the contacts - if you push the button, the 2 metal (copper) pieces touch each other (contact) and a bell (somewhere in the house...) is ringing.
In other words: you can give a signal to the servants without moving from your place.
If there are further questions, let me know :-)

Regards
Zolotnik

[dognose]

Hi Zolotnik,

The only thing connecting your item with the one originally posted is the fact that they are both shaped as pears. In the original example, as Cheryl has already stated, there is no opening for the wire to pass through.

Regards, Trev.

[Zolotnik]

Hi dognose -

The OP´s 5 photos do not show the interior and the description is vage - so everybody exept me knows for sure there is no hole - than this is no bellbutton in pear shape!
Regards
Zolotnik

[dragonflywink]

Nice pictures of the lovely Swedish pear along with the added lesson, though speaking for myself, am quite familiar with pendant bell-pushes, they were fairly common from the late 19th century here in the U.S, in various materials and shapes. The third image of the item appears to show solid metal above the threads in the socket, but agree that pictures can be deceptive - perhaps Dartsil will return to elaborate, but find it difficult to believe that he would have suggested use of the screwed-together item as a goblet or measure without mentioning the presence of holes in both sides that would make holding liquid an impossibility; also have a hard time seeing any purpose to the matching threads on both pieces if a bell-push.

~Cheryl