This expanded version of a 2007 post features images from The Writing of Stones by Roger Caillois (L'ecriture des pierres, 1970). Though long out-of-print, affordable copies sometimes show up on Amazon.
About the book, from the flaps:
The Writing of Stones is a fascinating meditation on the human imagination contemplating the interior of stones. Caillois examines patterns that are revealed by polishing sections of minerals such as agate, jasper, and onyx. He considers the impact these configurations have had upon the human imagination throughout history and he reviews man's attempt to categorize and explain them.
Marguerite Yourcenar [in her introduction] points out that "there had taken place in [his] intellect the equivalent of the Copernican revolution: man was no longer the center of the universe, except in the sense that the center is everywhere; man, like all the rest, was a cog in the whole system of turning wheels. Quite early on, having entered 'the forbidden laboratories,' Caillois applied himself to the study of diagonals which link the species, of the recurrent phenomena that act, so to speak as a matrix of forms." Caillois found the presence throughout the universe of a sensibility and a consciousness analogous to our own. One way which this consciousness expresses itself is in a "natural fantasy" that is evident in the pictures found in stones. Man's own aesthetic may then be no more than one of many manifestations of an all-pervasive aesthetic that reveals itself in the natural world
source: 50 Watts