Such a useful word when one is an aging person living in an aging house surrounded by aging stuff. The spoon above was a wedding gift 59 years ago--it's coin silver and was already old when we were given it. And it already had the soft patina that many years of use and polishing had given it. It's one of my favorite things.
A patina is a finish over a surface that develops over a period of time due to weather, stress and/or age. It is often used to refer to objects made of metal that develop a green film as a result of chemical reactions, as well as rust. However, the term can encompass any type of material, from metal to wood to leather. 
The goose/swan was originally shiny copper . . .
The floorboards were smooth--but being soft pine, have worn.
The front door bears the scratch marks of generations of dogs who wanted IN.
The basement door and my hand--both showing signs of weather and wear.
Ah, patina! Such a useful word.
