According to Cassell's Family Magazine Illustrated, 1885:[specify] It has long been known that certain flintstones emit a musical note when struck with other flints; and M. Baudre, a French musician, has constructed a piano on this principle.
The Star says that M. Baudry, the gentlemen who has made the instrument, was two years seeking for one particular stone, or tone—the terms being here almost synonymous.
M. Baudry entertained some friends on Saturday afternoon last with a performance on this curious instrument, which was much admired, not only for its novelty, but also for its musical effect.
The tones are unlike those of any known instrument, as may be readily comprehended by any one who knows the ring of a piece of flint, and possess a sharpness that renders the performance peculiar, though by no means unpleasing.
showing Honoré Baudre play his "geological piano", which has the stones held in a similar layout to a xylophone.
An 1875 article in The Times[2] refers to an instrument which its inventor, Honoré Baudre, had been exhibiting "during the last 20 years, principally in the Paris neighbourhood".