What is gold-bronze? (Frederick the Great medal)

mrfred

I have inherited a medal commemorating the Rosbach and Lissa victories by Frederick the Great of Prussia. After a lot of research on the internet -- by both me and my wife -- we found out that it is struck in 'goldbronze'. Here is a link that claims the alloy to be 85% copper and 15% zinc. You find this guy's guitar strings everywhere on the net; it seems that 'goldbronze' is a good material for guitar strings. infoplease.com has a different alloy reported.

Questions:

What is goldbronze and has it had coin metal value over the years, like gold, silver, bronze, copper and billon?
It occurs to me that the term 'goldbronze' may just be a fancy name for another bronze alloy.
Has it been used in coining and medals for a long time?
What are its long-term characteristics? This medal I've inherited has turned a very dark grey.

Here it is, btw, what do you think of it? The color of the scan, on my system at least, is very accurate.
Diameter is about 48mm; weight about 34 grams -->

cacheman

I think it is more likely that it is, or was, gold/bronze....meaning that it originally was gilded (in German, vergoldet). As you are aware, gilding gave a more impressive appearance to a piece than just bronze alone.

mrfred

Cache - perhaps. I did find one of these in much better condition in a catalog from a Dresden coin dealer, dated 2003, if I recall rightly. I cannot re-locate it on the web today. Anyway, that dealer listed it as 'goldbronze' (one word), not 'vergoldet' or 'gilded'. That's what lead me to the infoplease.com definition. I see no traces of gilding anywhere on the medal, but it is clearly worn and probably as circulated in its lifetime -- as a thaler? It's also been in our family since my great-great-grandfather came over in 1852, and has doubless been held and examined by countless family hands!

cacheman

With 85% copper and 15% zinc, there isn't much room to add gold too...perhaps the zinc (as opposed to the normally used tin) added a little softness to the copper and also toned down the red coppery color thereby giving it a gold appearance. Obviously I'm just guessing. In honesty, I think the value of the piece lies in its history more than anything else.

mrfred

I agree that the value is in the history of the piece rather than its metal content. I just got curious about the metal alloy, because I'd never heard of it.

As to the history -- to my family it is an heirloom. It is one of a batch of coins hand-carried by my great-great-grandfather when he moved the family (including my great-grandfather, who was like 13 at the time) to the USA in 1852-53. They settled in Indiana, and my grandfather was born and lived there until he was in his 40s. He then relocated to California, taking this medal and other coins with him. They were eventually distributed to his sons (my uncles) from one of whose estate I inherited this piece only this past December. There is family history.

I also find the history of the medal itself interesting. These two battles were like a month apart, and from the sources I checked, they were critical in coalescing Frederick's reign and power. The images on the medal are interesting. So far as I can determine, that's the smoke of battle cannons on the reverse.

The wear on the medal is quite interesting. Despite being handled by family members for the past 150-plus years, it looks to me like the thing actually circulated as a coin.

Udo

Even in Germany this name is rarely used!

Goldbronze

is just the name for a copper-brass alloy with a copper-contingent between 77% and 85%.
The alloy owes its name to its akin to gold look.