How can clay self-glaze? Efflorescence, that's how!

Every week I will introduce one little nuance on Egyptian paste. At this rate, we will acquire 52 characteristics of Egyptian paste in a year. Theoretically, anyone who can name 52 characteristics of Egyptian paste is somewhat of a master on the subject, no?
Moving on, efflorescence, is the term this week. I would describe it as a wicking of the salts in the Egyptian paste to the surface as it dries. The Egyptian paste has soluble salts in it; that is salts that are dissolved in water.
Here is an image of our miniature milking stool again; both before and after the firing to cone 06 (about 1000 C. degrees). It’s hard to see and photograph, but in the before picture there is a powder on the surface. The powder is like growing salt crystals. I’ll try to get a close-up photograph of the surface next time I fire a load of paste.