black dots in tea cup

[odarwin]

hi guys,

i recently got a pair of antique tea cups...
and upon cleaning them, i noticed spots of very fine black dots "embedded" in the glaze of the cups... and ideas as to what they are and are the normally seen in antique wares? and what does this say about the piece that i got?








thanks in advance!
-darwin

[betta]

Darwin, those larger dots are iron ore particles which got oxidised at high temperature in the kiln. They are found in porcelain regardless the age when the pottery was made and they are perfectly normal.
I am not sure about the smaller "sandy" ones.

[odarwin]

thanks for your replies,

after re-inspecting the cups carefully, i would say that the black dots are in the glaze, i would think that it came to contact with the cup while in the kiln...?

q-tip with slightly diluted bleach...? being brave... what's the effect of bleach on porcelain? would it damage it?

-darwin

[betta]

thanks for your replies,

after re-inspecting the cups carefully, i would say that the black dots are in the glaze, i would think that it came to contact with the cup while in the kiln...?

q-tip with slightly diluted bleach...? being brave... what's the effect of bleach on porcelain? would it damage it?

-darwin

My guess, it was already on the clay before the artist glazed the cup. Moreover if they are evenly distributed maybe they were already in the clay before forming.
In my opinion, I wouldn't be worry by them at all.

If it's in or beneath the glaze, you can't clean it up by any means without disrupting the surface.
Bleach won't help either, because these particles aren't organic materials.
BTW diluted bleach won't do harm to porcelain. It harms only organics on the surface of it, like tea stain which seasons yixing pot, but not the clay itself.

[Smells_Familiar]

i've got one porcelain cup that started out white and now has a patch of those pin prick sized black dots. upon close inspection i found that the glaze had tiny pores in that area. i assume that tea has gotten down in them causing the black tiny dots on my cup.

[edkrueger]

That cup is very good quality. Lower quality cups will have a lot more iron spots. Having few iron spots are actually desirable. Many porcelain and celadon potters purposely cause them using filings –when they use gas kilns.

[coloradopu]

sometimes in large bottle type kilns or wood fire kilns in witch they use a sort of box to protect the ware from the soot. you will get this sort of defect....... some would call it that ....others character. any who in the bottle kiln soot or any other fine particles fall onto the ware and cause this black spots and in other cases its not black at first were a super heated particle falls on the glaze and actually burns a hole in it causing a pour to form and yes it will and does fill with tea. as fare as the little boxes used to stop this well not being too careful in your work will result in dust falling from the lid onto the glaze and this dust becomes Incorporated in the glaze forming a sort of small pit but still smooth but not like the pore hole but on top . its all good but some just can't stand a spot on the inside of there cup as it makes them think it dirt. if you like the cup just don't look ...... ha. ha.

sorry sort of run on

[Victoria]

By the way, those are beautiful and have a great shape.
Congrats!

[odarwin]

thanks for your replies again guys,

ill look carefully again on the possibility of the glaze having very small pores in the area's that have those black dots and see if i can rule out that possibility.

i actually just wanted to get opinion on what those are...
this is actually my 2nd and 3rd antique cup, (first one was a de hua shipwreck piece) and haven't gotten myself to use any of them yet... i dont know, i just have a feeling of hesitation. i do think that the black dots give it character, and with the color of the cups, it does look like a piece from long long ago.

-darwin

[MarshalN]

They look great. Black dots are entirely normal -- I think calling them flaws might be the best way to characterize them.

[sriracha]

I was under the impression dots/flecks/spots meant low quality material..but perhaps not so bad as I thought then..? =)