decrepitate salts.    From Wordnet, Princeton University. 

The crystals are in the form of small cubes and contain no water of crystallization; some water is, however, held in cavities in the crystals and causes the salt to decrepitate when heated.    From Wordnik.com.  [An Elementary Study of Chemistry] Reference

Heated to rednefs for half an hour, it does not decrepitate, but lofes 45 per ct. of its weight.    From Wordnik.com.  [Elements of Mineralogy: By Richard Kirwan, ...] Reference

(decrepitate or spell) during firing.    From Wordnik.com.  [3. Technical and Production Information] Reference