effloresce

verb5

1. •
   To burst into bloom; to flower.
2. •
   (figurative) Of something hidden: to come forth, to emerge; also, to reach full glory or power.

   • No more in tears / She lingers 'mong the years, / No more she watcheth through the lonesome night; / Her night is past, / No shadow on her cast, / She effloresceth 'mong the flowers in light. — 1893
3. •
   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.

   • The salts which effloresce from old walls, are nitre more or less pure, quadrangular nitre, mineral alkali in abundance, more or less pure, and mixed with calcareous earth; [...] — 1790
4. •
   Of the surface of a material: to become covered with a powdery salt (as described in sense 3.2).

   • This stone is perpetually efflorescing, and forming the salt called Sulphate of Iron: vulgarly, Copperas. — 1799
5. •
   Of a substance: to change from being crystalline to powdery by losing water of crystallization.

   • This is the very case with the Pyrites that consist only of iron and sulphur; yet some of them, as we said before, do not effloresce spontaneously and turn to Vitriol. — 1758