It was filled with a waxlike substance, the middle of which had a round indentation, in the shape of a small ball.

NEWYORKER: Creation Myth

In particular one part of it - calcium silicate hydrate - refused all attempts to be analysed under an electron microscope or by nano-indentation.

BBC: By Ian Hardy

This rocker sits flush with the side of the device, the indentation in the middle serving as the only thing that sets it apart from the left extent.

ENGADGET: iPod nano review (2012)

He could find no damage one small indentation, but nothing dangerous.

NEWYORKER: Among Animals and Plants

But "every one of those stops was memorable, " Closson says, explaining why, despite a black eye and a permanent indentation in his head, he signed up for Nemitz's trip through Tuscany in 1998.

FORBES: Antique Roadshow