I’ve been using this handmade black clay cup every day for water, tea, and coffee, and the color has slowly started to change.
Some parts look lighter yellow or dark blue or green and softer now, especially around the rim and interior. I’m wondering how potters would read this: is it mineral deposit, tea staining, surface wear, absorption, or something about the clay/firing?
More broadly, do you think this kind of change is damage, patina, or part of the life of the object?
I personally find it beautiful, but I’d love to learn what might be happening materially. For context, it's a handmade black pottery cup from a Himalayan pottery tradition. From what I understand, it was low-fired and blackened through a carbon-smoking/reduction process rather than glazed.