Pure earth does not petrify, because the predominance of dryness over [i.e. in] the earth endows it not with coherence but rather with crumbliness. In general, stone is formed in two ways only (a) through the hardening of clay, and (b) by the congelation [of waters].
Avicenna, Alfred (of Sareshel.), Eric John Holmyard (1927). “Avicennae De Congelatione Et Conglutinatione Lapidum”, AMS Press
![Pure earth does not petrify, because the predominance of dryness over [i.e. in] the earth endows it not with coherence but rather with crumbliness. In general, stone is formed in two ways only (a) through the hardening](http://cdn.quoteddaily.com/images/avicenna/pure-earth-does-not-petrify-because-the-predominance-of-dryness-over-ie-in-the-earth-endows-it-not-with-coherence.jpg)