mantel / mantle are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
mantel: (noun) shelf that projects from wall above fireplace.
mantle: (noun) the cloak as a symbol of authority. (noun) United States baseball player (1931-1997). (noun) the layer of the earth between the crust and the core. (noun) (zoology) a protective layer of epidermis in mollusks or brachiopods that secretes a substance forming the shell. (verb) spread over a surface, like a mantle. (verb) cover like a mantle.
mantel: m·AE·n·t·ah·l
mantle: m·AE·n·t·ah·l
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)