effloresce

Short definition from Wiktionary

Verb

1. 1
   To burst into bloom; to flower.
2. 2
   Of something hidden: to come forth, to emerge; also, to reach full glory or power.
3. 3
   Senses relating to chemistry: Of a substance: to change from being crystalline to powdery by losing water of crystallization.
4. 4
   Senses relating to chemistry: Of a salt: to seep through some material (bricks, concrete, earth, rock, etc.) in a dissolved state, and then crystallize on a surface in a powdery form.
5. 5
   Senses relating to chemistry: Of the surface of a material: to become covered with a powdery salt (as described in sense 3.2).