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<p>[QUOTE=&quot;robinjojo, post: 8303365, member: 110226&quot;]Your coin looks as if it has typical hard green deposits.&nbsp; I have many ancients with these spots.&nbsp; I don&#039;t think that is bronze disease.&nbsp; Active bronze disease is a very pale green to almost white powdery deposit that can be scratched off in most instances with a finger nail.&nbsp; The hard green deposits are not chemically active and they are usually hard as cement, so they don&#039;t remove easily.</p><p><br /></p><p>I suggest that you set the coin aside and keep an eye on it.&nbsp; If the green area show any change, developing powdery areas, then the coin needs to be treated for bronze disease, since the corrosive process will eat into the coin.</p><p><br /></p><p>There is a chemical for bronze disease, sodium sesquicarbonate, which will neutralize the corrosive process.&nbsp; The down side is that this chemical also, if the coin soaks for many days, will remove most or all of the patina as well.&nbsp; This measure should only be taken with coins with confirmed bronze disease.</p><p><br /></p><p>Here&#039;s a coin that spent several weeks in a sodium sesquicarbonate (washing soda) bath.&nbsp; This Turkoman AE dirham had a bad case of bronze disease on the reverse in a depression created by a flan lamination.&nbsp; Copper oxide deposits built up over the centuries, trapping moisture as well.&nbsp; To save the coin, I had soak the coin and remove it from time to time to scrape away the acidic deposit.&nbsp; Now, the coin is apparently free of the problem, but at a cost.</p><p><br /></p><p>[ATTACH=full]1469364[/ATTACH] </p><p><br /></p><p>The original patina has been stripped away.&nbsp; The lamination, the site of the bronze disease development is on the reverse, a roughly rectangular pit.&nbsp; It seems that the flan had some internal weak spots, which resulted in the crack leading to the lamination, where the metal either separated from the flan during the striking, or afterwards during circulation.[/QUOTE]</p><p><br /></p>

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