What is this close-up picture? (WotsThat: Whitewashed wall texture (macro))

Question

What object is shown in this zoomed-in close-up photo?

FlintstoneJr · Accepted Answer

Whitewashed wall texture (macro). Traditional whitewash is made from slaked lime and water, and as it dries it reacts with carbon dioxide in the air to slowly turn back into limestone, which is why old whitewashed walls can last for generations with occasional refreshing.

Answer: Whitewashed wall texture (macro)

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