A mantel is a shelf above a fireplace.*
Mantle can be a noun or a verb and has a variety of meanings. Most commonly, mantle is used to refer to a cloak (as a garment or as “a figurative cloak symbolizing preeminence or authority”) or to the part of the earth’s interior that lies beneath the crust.
The mantle is approximately 1,800 miles thick and makes up 84% of the planet’s total volume. (National Geographic Society)
Dostoevsky: The Mantle of the Prophet is about the Russian writer and philosopher.
When she withdrew her mantle, I saw that her shoulders were bare.
Finally, a woman has taken on the mantle of leadership.
Mantle can also mean “something that covers, enfolds, or envelops.”
A mantle of snow covered the ground.
Our vision obscured by the thick mantle of smoke, we crept along the ground until we reached safety.
If you are a baseball fan, remember Mickey Mantle, the New York Yankee who was inducted into the National Baseball Hall of Fame in 1974:
The Mick wore the mantle of success with pride.
*Mantel can also mean “a beam, stone, or arch serving as a lintel to support the masonry above a fireplace” and “the finish around a fireplace,” but most references will be to the shelf above a fireplace. (Mantle is a variant spelling, but mantel is preferred.)