From Longman Dictionary of Contemporary Englishmantelpieceman‧tel‧piece /ˈmæntlpiːs/ (also mantel /ˈmæntl/ especially American English, mantelshelf /ˈmæntlʃelf/ British English) noun [countable] 
DHa wooden or stone shelf which is the top part of a frame surrounding a fireplace The clock on the mantelpiece struck 10.
DHa wooden or stone shelf which is the top part of a frame surrounding a fireplace The clock on the mantelpiece struck 10.Examples from the Corpus
mantelpiece• The china money jar on the kitchen mantelpiece that contained their emergency funds lay shattered and empty on the floor.• Through the slate-floored living-room, with its exposed beams, open grate and massive heart-of-oak mantelpiece, was the kitchen.• Evans had gone through into the lounge and was standing leaning against the mantelpiece in the classic pose of grief.• Silver cups - golfing trophies - crammed the mantelpiece over a huge arched brick fireplace.• She emptied the dustpan and searched for something else to do, straightening the Christmas cards on the mantelpiece as she passed.• He noticed the picture frames on the mantelpiece had been turned to the wall.• On the mantelpiece she displayed photographs of dead people, propped up in their coffins, looking glum.• On the mantelpiece there was a small lamp with a crimson shade and I switched it on. 