What is the reason for the black line of lobular rosewood plate after a period of time?

This is normal. The lobular rosewood is exposed to the air for a long time, and will gradually darken after being oxidized by the air, and the lobular rosewood itself will have a certain texture. The oxidation color generally begins to darken from the place where the annual rings grow, that is, the circle. After a long time, the whole bead will turn black. If you have any questions, you can look at my Baidu name or trust me privately.

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