Definition of "flintstone"

The very poor will sometimes adorn the graves of those they love with oystershells, or flintstones, or small plaster busts, or tiles […]

1858, Ecclesiological Society, The Ecclesiologist

At times when there was inadequate sunlight to focus through the lens, the king struck flintstones to ignite the flame in the same way.

1991, Damrong Rajanubhab Damrongrāchānuphāp, Journey through Burma in 1936

They stacked flintstones in a way that permitted night winds to pass around them and cool them so they collected moisture.

1964, United States Dept. of Agriculture, Yearbook of Agriculture