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<p>[QUOTE="GDJMSP, post: 3375348, member: 112"]Your quote made me do something something today that I have been considering doing for a a great many years - find out just how hard coin gold (90% gold) really is. But I just never took the time to do it - today I did.</p><p><br /></p><p>Nobody ever disputes that gold is softer than silver - but that's when you're talking about pure gold and pure silver. And I guess what started me thinking about this subject many years ago was the scene that has been replayed in a thousand movies where somebody bites a gold coin. And most folks always assume that they are doing that to make sure it's real gold by biting to see if it is soft and therefore genuine. But they are not biting the coin to see if it is soft - they are biting it to see if it is hard, and therefore genuine !</p><p><br /></p><p>And, my experience from carrying a 1 oz AGE in my pocket for about 20 years taught me that gold coins wear very, very well - and lose almost no metal (by weight) with wear even down to grades as low as F. And I think just about everybody has seen the pictures I've posted of one of those coins. But I'll post 'em again anyway.</p><p><br /></p><p>[ATTACH=full]895306[/ATTACH] </p><p><br /></p><p>[ATTACH=full]895307[/ATTACH] </p><p><br /></p><p>And over the years of course on this forum, others like it, in everyday discussions in person over the years, pretty much everybody has always assumed that gold coins were soft, softer than silver coins and therefore more subject to wear than silver coins would be. And you can count me among those who made that same assumption - because gold is softer than silver so it seems to stand to reason. Today however, I was surprised.</p><p><br /></p><p>This is why. What I found out was that coin gold (90% gold) is actually harder than coin silver (90% silver). Coin gold has a Vickers Hardness of 197, and coin silver has a Vickers Hardness of 148. So after all these years what I have found out is that gold coins aren't made of such a soft metal after all, gold coins are actually harder than silver coins. That means they are less susceptible to contact marks than silver coins are, and they wear better than silver coins. Like I said, I was surprised, but at last I had an answer as to why those gold coins in my pocket always wore so well <img src="styles/default/xenforo/clear.png" class="mceSmilieSprite mceSmilie1" alt=":)" unselectable="on" unselectable="on" /></p><p><br /></p><p>And no I'm not just gonna make claims like that and not back it up. I'm gonna show ya the same things I found. This for example - </p><p><br /></p><p><img src="https://www.911metallurgist.com/blog/wp-content/uploads/2016/10/Gold-Alloys.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /> </p><p><br /></p><p>And here's the link for it - </p><p><br /></p><p> <a href="https://www.google.ca/imgres?imgurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fwp-content%2Fuploads%2F2016%2F10%2FGold-Alloys.jpg&imgrefurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fgold-alloys&docid=q1kZ7LREyFDPoM&tbnid=5LWees0a9flDLM%3A&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500&h=390&safe=images&bih=688&biw=1455&q=hardness%20of%2090%25%20gold&ved=0ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ&iact=mrc&uact=8#h=390&imgdii=5LWees0a9flDLM:&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://www.google.ca/imgres?imgurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fwp-content%2Fuploads%2F2016%2F10%2FGold-Alloys.jpg&imgrefurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fgold-alloys&docid=q1kZ7LREyFDPoM&tbnid=5LWees0a9flDLM%3A&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500&h=390&safe=images&bih=688&biw=1455&q=hardness%20of%2090%25%20gold&ved=0ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ&iact=mrc&uact=8#h=390&imgdii=5LWees0a9flDLM:&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500" rel="nofollow">https://www.google.ca/imgres?imgurl=https://www.911metallurgist.com/blog/wp-content/uploads/2016/10/Gold-Alloys.jpg&imgrefurl=https://www.911metallurgist.com/blog/gold-alloys&docid=q1kZ7LREyFDPoM&tbnid=5LWees0a9flDLM:&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500&h=390&safe=images&bih=688&biw=1455&q=hardness of 90% gold&ved=0ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ&iact=mrc&uact=8#h=390&imgdii=5LWees0a9flDLM:&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500</a></p><p><br /></p><p>And for those that don't know, 21 karat gold is 90% gold - that's where the Vickers Hardness of 197 comes from.</p><p><br /></p><p>And the 21 karat being 90% comes from here - </p><p><br /></p><p>[ATTACH=full]895303[/ATTACH]</p><p><br /></p><p>And the link for it - </p><p><a href="https://en.wikipedia.org/wiki/Fineness" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://en.wikipedia.org/wiki/Fineness" rel="nofollow">https://en.wikipedia.org/wiki/Fineness</a></p><p><br /></p><p>And the number I quoted for the Vickers Hardness of coin silver comes from here - </p><p><br /></p><p>[ATTACH=full]895302[/ATTACH]</p><p><br /></p><p><br /></p><p>And the link for that - </p><p><a href="http://what-when-how.com/materialsparts-and-finishes/silver-and-alloys/" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://what-when-how.com/materialsparts-and-finishes/silver-and-alloys/" rel="nofollow">http://what-when-how.com/materialsparts-and-finishes/silver-and-alloys/</a></p><p><br /></p><p>So who else is as surprised as I am ?[/QUOTE]</p><p><br /></p>
[QUOTE="GDJMSP, post: 3375348, member: 112"]Your quote made me do something something today that I have been considering doing for a a great many years - find out just how hard coin gold (90% gold) really is. But I just never took the time to do it - today I did. Nobody ever disputes that gold is softer than silver - but that's when you're talking about pure gold and pure silver. And I guess what started me thinking about this subject many years ago was the scene that has been replayed in a thousand movies where somebody bites a gold coin. And most folks always assume that they are doing that to make sure it's real gold by biting to see if it is soft and therefore genuine. But they are not biting the coin to see if it is soft - they are biting it to see if it is hard, and therefore genuine ! And, my experience from carrying a 1 oz AGE in my pocket for about 20 years taught me that gold coins wear very, very well - and lose almost no metal (by weight) with wear even down to grades as low as F. And I think just about everybody has seen the pictures I've posted of one of those coins. But I'll post 'em again anyway. [ATTACH=full]895306[/ATTACH] [ATTACH=full]895307[/ATTACH] And over the years of course on this forum, others like it, in everyday discussions in person over the years, pretty much everybody has always assumed that gold coins were soft, softer than silver coins and therefore more subject to wear than silver coins would be. And you can count me among those who made that same assumption - because gold is softer than silver so it seems to stand to reason. Today however, I was surprised. This is why. What I found out was that coin gold (90% gold) is actually harder than coin silver (90% silver). Coin gold has a Vickers Hardness of 197, and coin silver has a Vickers Hardness of 148. So after all these years what I have found out is that gold coins aren't made of such a soft metal after all, gold coins are actually harder than silver coins. That means they are less susceptible to contact marks than silver coins are, and they wear better than silver coins. Like I said, I was surprised, but at last I had an answer as to why those gold coins in my pocket always wore so well :) And no I'm not just gonna make claims like that and not back it up. I'm gonna show ya the same things I found. This for example - [IMG]https://www.911metallurgist.com/blog/wp-content/uploads/2016/10/Gold-Alloys.jpg[/IMG] And here's the link for it - [url]https://www.google.ca/imgres?imgurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fwp-content%2Fuploads%2F2016%2F10%2FGold-Alloys.jpg&imgrefurl=https%3A%2F%2Fwww.911metallurgist.com%2Fblog%2Fgold-alloys&docid=q1kZ7LREyFDPoM&tbnid=5LWees0a9flDLM%3A&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500&h=390&safe=images&bih=688&biw=1455&q=hardness%20of%2090%25%20gold&ved=0ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ&iact=mrc&uact=8#h=390&imgdii=5LWees0a9flDLM:&vet=10ahUKEwiY5ZmU5MzgAhVwkuAKHWyfCCcQMwg_KAEwAQ..i&w=500[/url] And for those that don't know, 21 karat gold is 90% gold - that's where the Vickers Hardness of 197 comes from. And the 21 karat being 90% comes from here - [ATTACH=full]895303[/ATTACH] And the link for it - [url]https://en.wikipedia.org/wiki/Fineness[/url] And the number I quoted for the Vickers Hardness of coin silver comes from here - [ATTACH=full]895302[/ATTACH] And the link for that - [url]http://what-when-how.com/materialsparts-and-finishes/silver-and-alloys/[/url] So who else is as surprised as I am ?[/QUOTE]
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