👉 A patina is a type of mineral or rock layer that forms on an object due to the accumulation and deposition of minerals over time. It can be found in various types of rocks, including granite, basalt, and marble. In the context of geology, a "patina" refers to a deposit of minerals or other matter that has accumulated over geological time. This process can occur due to weathering, erosion, or chemical reactions between different layers of rock. The patina can be