Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Patina
Summary
Patina (pəˈtiːnə or ˈpætᵻnə) is a thin layer that variously forms on the surface of copper, brass, bronze and similar metals and metal alloys (tarnish produced by oxidation or other chemical processes) or certain stones and wooden furniture (sheen produced by age, wear, and polishing), or any similar acquired change of a surface through age and exposure.
Additionally, the term is used to describe the aging of high-quality leather. The patinas on leather goods are unique to the type of leather, frequency of use, and exposure.
Patinas can provide a protective covering to materials that would otherwise be damaged by corrosion or weathering. They may also be aesthetically appealing.
On metal, patina is a coating of various chemical compounds such as oxides, carbonates, sulfides, or sulfates formed on the surface during exposure to atmospheric elements (oxygen, rain, acid rain, carbon dioxide, sulfur-bearing compounds). In common parlance, weathering rust on steel is often mistakenly referred to as patina. Patina also refers to accumulated changes in surface texture and color that result from normal use of an object such as a coin or a piece of furniture over time.
Archaeologists also use the term patina to refer to a corticated layer that develops over time that is due to a range of complex factors on flint tools and ancient stone monuments. This has led stone tool analysts in recent times to generally prefer the term cortification as a better term to describe the process than patination.
In geology and geomorphology, the term patina is used to refer to discolored film or thin outer layer produced either on or within the surface of a rock or other material by either the development of a weathering rind within the surface of a rock, the formation of desert varnish on the surface of a rock, or combination of both. It also refers to development as the result of weathering of a case-hardened layer, called cortex by geologists, within the surface of either a flint or chert nodule.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.