FORVM`s Classical Numismatics Discussion Board

Numismatic and History Discussion Forums => Ancient Coin Forum => Topic started by: TRPOT on July 29, 2012, 06:32:34 pm

Title: Bites
Post by: TRPOT on July 29, 2012, 06:32:34 pm
related to a jokey post I made about another coin...

In old westerns guys always seemed to bite coins when they got paid to make sure they were solid gold. Are there ever teeth marks found on gold coins? I think it'd be pretty cool to have an ancient coin with bite marks.  ;D
Title: Re: Bites
Post by: Andrew McCabe on July 29, 2012, 06:36:44 pm
related to a jokey post I made about another coin...

In old westerns guys always seemed to bite coins when they got paid to make sure they were solid gold. Are there ever teeth marks found on gold coins? I think it'd be pretty cool to have an ancient coin with bite marks.  ;D

I guess if they were gold, there would not be teeth marks. But someone's coin collection surely includes is a gold-covered lead fake with cowboy teeth marks. Weren't they lead fakes that the bite protected against? As a kid I used to test coins with my teeth, without any idea what I was testing for or why; I'd just seen it in the movies.
Title: Re: Bites
Post by: TRPOT on July 29, 2012, 06:38:11 pm
related to a jokey post I made about another coin...

In old westerns guys always seemed to bite coins when they got paid to make sure they were solid gold. Are there ever teeth marks found on gold coins? I think it'd be pretty cool to have an ancient coin with bite marks.  ;D

I guess if they were gold, there would not be teeth marks. But someone's coin collection surely includes is a gold-covered lead fake with cowboy teeth marks. Wasn't it lead fakes that the bite protected against?

Maybe. I've never tried to bite a gold coin so I don't actually know how hard it is. I thought it'd be about as soft as lead.
Title: Re: Bites
Post by: Robert_Brenchley on July 30, 2012, 05:39:59 pm
I bet you could break your teeth on lead!
Title: Re: Bites
Post by: Andrew McCabe on July 30, 2012, 06:02:48 pm
Moh's hardness of lead is 1.5; of gold is 2.5. Each Moh unit represents about a doubling of hardness so in practice this means pure gold is about twice as hard as pure lead. For practical comparisons, a fingernail has a Moh hardness of about 2.2-2.5 (able to cut lead but unable to scratch gold). Teeth are harder than both. I don't know what this means in practice regarding biting gold coins.
Title: Re: Bites
Post by: crawforde on July 30, 2012, 06:19:54 pm
I have a silver-covered lead-filled 8 reales coin that was destroyed by chop marks, they kind of like the Chinese version of banker's marks. 
I will dig it out and look for teeth marks later this week. If there are any I will take pictures, the effects of the chop marks and resulting delamination are kind of interesting.

Eric

PS Does anyone have an old sovereign they would like to bite for a test ?  ;)

Title: Re: Bites
Post by: TRPOT on July 30, 2012, 06:30:59 pm
I bet you could break your teeth on lead!

I've used my teeth to pinch lead sinkers on my fishing line. I figured an aureus would feel as hard as a lead sinker.
Title: Re: Bites
Post by: Robert_Brenchley on July 31, 2012, 04:47:46 pm
So have I, but then they're cut almost all the way through, and it's not like biting into a solid chunk of the stuff.
Title: Re: Bites
Post by: TRPOT on July 31, 2012, 06:39:42 pm
I've seen some bullets that have been chewed on pretty good, but then again the people who bit them were probably getting a limb sawed off at the time. That might motivate one to bite with considerably more force than one would normally be willing to use on such an object.