Lime pops!

 About a month ago, I wrote about making a sign in clay, to remind myself about not wasting water. 

Here's a link, if you missed it.

I wanted it glazed in colors that looked like water - greens and blues - and here's what came out of the kiln. 

Right above the lettering, there was a lime pop. When a bit of plaster infiltrates the clay, and then the piece gets fired - the bit of plaster "explodes" within the clay. 

Sometimes it can be a pretty big "explosion" that blows out the whole side of a pot. Here's a good example of a pop in the bottom rim of a bowl. 

In the case of my sign, the piece of lime caused the clay to explode and lift ... not the worst defect in the world, IMO.