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<p>[QUOTE="jgenn, post: 3995126, member: 78525"]This is certainly a forgery simply based on the incorrect assayer initials. But you might wonder why it looks so good and has evidence of a fair amount of circulation. Given that you say the weight is accurate, it might actually have 80% or more silver.</p><p><br /></p><p>Several countries forged issues like these in massive quantities for trade with Southeast Asia in the late 1800's to early 1900s because the silver traders greatly preferred the 8 reales of Charles IV above all other silver trade coins. As the schroff's got better at measuring the silver content, forgers were forced to increase the silver content to near accurate levels. See <a href="https://www.amazon.com/Counterfeit-Portrait-Eight-Reales-Real-Reales/dp/0990802906" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://www.amazon.com/Counterfeit-Portrait-Eight-Reales-Real-Reales/dp/0990802906" rel="nofollow">Bob Gurney's book</a> for the full details.</p><p><br /></p><p>Some other things to check, because most of these forgeries don't have obvious design flaws like impossible assayer initials: </p><p><br /></p><p>Look for two overlaps in the edge design. The genuine issues were made on a parallel edging mill, a <a href="http://Castaing machine" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://Castaing machine" rel="nofollow">Castaing machine</a> or something very similar and they would leave a short area of overlap in two spots on directly opposite sides and the size of the overlap, generally 2-3 rectangle/circle devices, will be identical in length. </p><p><br /></p><p>Measure the specific gravity carefully to make sure it's 90% silver. </p><p><br /></p><p>Neither characteristic is a guarantee of authenticity. If you really want to be sure the alloy is correct, an XRF scan should reveal a small percentage of gold for genuine issues from the Mexico City mint. The silver mined in Mexico contains small amounts of gold and the refining techniques of that time were not capable of separating out those small amounts from the silver.[/QUOTE]</p><p><br /></p>
[QUOTE="jgenn, post: 3995126, member: 78525"]This is certainly a forgery simply based on the incorrect assayer initials. But you might wonder why it looks so good and has evidence of a fair amount of circulation. Given that you say the weight is accurate, it might actually have 80% or more silver. Several countries forged issues like these in massive quantities for trade with Southeast Asia in the late 1800's to early 1900s because the silver traders greatly preferred the 8 reales of Charles IV above all other silver trade coins. As the schroff's got better at measuring the silver content, forgers were forced to increase the silver content to near accurate levels. See [URL='https://www.amazon.com/Counterfeit-Portrait-Eight-Reales-Real-Reales/dp/0990802906']Bob Gurney's book[/URL] for the full details. Some other things to check, because most of these forgeries don't have obvious design flaws like impossible assayer initials: Look for two overlaps in the edge design. The genuine issues were made on a parallel edging mill, a [URL='http://Castaing machine']Castaing machine[/URL] or something very similar and they would leave a short area of overlap in two spots on directly opposite sides and the size of the overlap, generally 2-3 rectangle/circle devices, will be identical in length. Measure the specific gravity carefully to make sure it's 90% silver. Neither characteristic is a guarantee of authenticity. If you really want to be sure the alloy is correct, an XRF scan should reveal a small percentage of gold for genuine issues from the Mexico City mint. The silver mined in Mexico contains small amounts of gold and the refining techniques of that time were not capable of separating out those small amounts from the silver.[/QUOTE]
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1804 Mexico 8 Reales - Need Help
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