Strange deposit inside kyusu

[Mterpstra]

Hey everyone

I saw a nice kyusu for sale on a website in my country. There are some issues with it though. There is a weird deposit inside it. Can you guys help me figure out what it is? My first guess would be just mineral deposit from water. The pot has been used by an old lady who made green tea, probably sencha, in it. It's the fifth picture in the link: http://link.marktplaats.nl/m851483966

Further more, do you guys have some idea on where it might be made. Stupid enough the mark is nog visible on the previous link, but it is on this on this link third picture http://link.marktplaats.nl/m845638483

Oh, and I don't think it's yixing, but that doesn't matter if it's Japanese origin.

Thanks a bunch

[Poseidon]

It looks like dust, dirt, or mold. All of which can be fixed with a good wash/gental scrub and a good boiling to kill the bacteria. As for the kyusu in gereral, I would give it a pass. You can find lots of pots around that price brand new online.

Edit: After a second look, this does have a nice ball filter. That may clue some more knowledgeable teachat members in about the quality. The chop seems to be blurry though. You can get more information with a clean clear shot of the chop(or stamp).

[Chip]

It is definitely a Kyusu, and likely Japanese made. Though some low end versions are made for Japan in China. But this looks Japan made.

The stains are simply mineral and tea. Tea stains cling quite readily to scale. The pot was used quite heavily, and maybe for more than Japanese greens.

[Mterpstra]

Thanks guys for the quick replies! I asked for more info, but the pot is passed on by someone who passed away. I can probably get something of the price. New pots for that price including shipping are usually not so good quality though.

I was planning on using it for medium grade oolongs anyway, also as you say, Chip, because it has been used so often. It´s for at work when I don´t have lot´s of time to fully enjoy tea as I can do at home.