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9148 Carnelian Agate Cabochon Loose Carnelian Agate Cabochon for Jewelry Making 26 X 18 X 8 Mm 26 Ct Cabochons From Thegemdealer - Australia

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I put my grinder in a mixture of hydrogen peroxide and salt, it came out black and full of gunk as a result, it was silver before, can anyone explain this?

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