Yixing - black dots

[TokyoB]

I have a question about zisha pots. On some there are very small black dots on the surface. When I say "on the surface" I mean that they look like something melted onto the surface and are sitting slightly raised above the surface. Some teapots have just one, or two of these and some have several. Other pots don't seem to have these at all. What is the source of these small black dots? I know that larger dots, which are more burned or pitted into the surface are a result of open firing, but I'm not sure about these smaller dots. Are they from kilns that are oil fired? or something else?

[Poohblah]

Moles.

[Chip]

Iron?

[tingjunkie]

I would have said from open firing, but you seem to be referring to something different. Any pics of what you are talking about?

[apolon]

I think that's iron or manganese in the clay.

[Drax]

Somebody had linked a few posts by chrl42 over on teadrunk in another recent thread here... in any case, this one here might answer your question? Like Chip and apolon, he suggests it is due to iron or manganese.