Need help to identify zhuni clay purity

[betta]

Dear all,

Nice to meet you ^-^
I'm a newbie in the chinese tea world. I'm glad to find a very active forum for all kind of teas here.
I have one doubt and hope if anyone kind enough to help me with this.
Intend to acquire a zhuni pot, I mean the authentic one, not mixture of hong ni, but I'm confused because it is said to be very rare or those on the market are mixed zhuni.
Does anyone know how to differentiate mixed zhuni from pure zhuni?
Has anyone acquired 'lao zhu ni pots' from Yunnan Sourcing or know if they are of pure zhuni?
Thx

[olivierco]

Does anyone know how to differentiate mixed zhuni from pure zhuni?

That is quite a difficult question. If the teapot is cheap, it is definitively not good zhuni. But if it is expensive it doesn't mean it is good zhuni...

Don't be too focused on the teapot, be more focused on the tea.

For most teas, basic teapot (porcelain, glass) or kyuusu is all what you need.

If you are on Puer, buy a decent teapot (you should anyway need a zhuni, zisha or duani only for Puer and oolongs although you can brew them in a gaiwan): small capacity (10 to 20 cl) and good heat keeping. I bought mine for about 50€ (75 US$) from a Taiwanese vendor because I liked the teas he sells ans also because I tend to think that food related item safety is stricter in Taiwan than in China.

[betta]

Thanks olivierco. I agree with your point.
I'm not afraid of any external dirt on the pot as it can always be cleaned with any chemical oxidation, but I do afraid of those mixed in the clay. Once the clay mixed with any unhealthy material (e.g. lead), then it's useless.
I do intend to use the pot for oolong, especially high mountain formosa oolong.
Could you inform me about the taiwanese vendor you mentioned about?

[olivierco]

Here is the link to his blog: Stéphane Teamasters

He offers good teas as well (I ordered from him four puers and seven oolongs last year with two teapots and I sure will order some more teas later this year when my Japenese tea phase is slowing down).

[Salsero]

Has anyone acquired 'lao zhu ni pots' from Yunnan Sourcing or know if they are of pure zhuni?
Thx

I don't know how to distinguish, but I have read that true zhuni is very rare now and more expensive than gold. I have bought several pots from Yunnan Sourcing, however, and like them and trust Scott to have good merchandise. I have never gotten a pot from Stephane at TeaMasters. My impression is that his pots are even better quality, and also rather expensive.

Glad to see you post here. Hope to see more of you!

[betta]

Thanks Salsero and Olivierco for the info. From your testimony (and of course your experiences) I can trust the tea and teawares from the vendors you recommended.

[hop_goblin]

Actually " true"Zhuni is supposed to have gone extinct roughly 30 years ago and the only examples that are on the market were either made during this period or made from stored clay. If you want a true zhuni you will no doubt have to purchase a vintage pot. I got lucky and found one from China made by the famous ErPu studio!

It has been my understanding that what vendors call Zhuni on the market today is a type of Hongni which has been sifted and allowed to settle and float to the top. The layer is skimmed off and subsequently processed and to make pots. However, if you must find a zhuni equivelent, start with a nice "ping" sound when you tap it. It should never sound like a dull thump. Secondly, look for what are called crawl marks. Crawl marks are tiny striations resembling "waves" on the surface of the clay which are caused by clay shrinkage, very indicative of zhuni or new zhuni. 3rd, look inside the pot towards the back, if should see and feel a "jointline". This jointline was placed by the maker to keep the pot intact while firing, again due to the amount of shrinkage which will occur in the kiln as a consequence of "zhuni". If you don't see it, then it is probably not a zhuni. 4th, it should have a nice creamy and smooth texture.. somtimes even shinny. You can find rough zhuni on the maket but it is generally due to sand being mixed in the clay but that is a different discussion.

[betta]

Hop_goblin, those are awesome info you shared with us
Is the joint line a must have characteristic for genuine true zhuni?
You're lucky to acquire such a fine genuine piece zhuni, I envy you

[hop_goblin]

Thanks. Yes, a joint line must be present. With zhuni, the clay will shrink more than any other during the kilning process. The jointline keeps it from comming apart. If you scan the HouDe blog, you will find a reference to the jointline.

[ABx]

Hmm, that sounds like a bit of a myth to me. All clay shrinks during firing, some more than others, but the whole piece is going to shrink at the same rate and I've never heard of needing anything to hold a piece together - even with clays that shrink 15-20%.

With all yixing pots the artist is going to pound the clay into a sheet, wrap that sheet into a cylinder, and then shape it with paddles (turning it while tapping it with paddles). I can see the potential for a "joint line" in any traditionally made pot, but don't know why you'd need it in any particular clay.

This is just my impression as someone that works with clay. I could be lacking some info and be completely wrong, but I am very skeptical, but the only special consideration I've heard with high-shrinkage clays is just to make your pieces bigger so they don't turn out too tiny after being fired and not making your pieces too thick. Too thick and they can crack, but we're talking about pieces that are inches thick, not millimeters.

[betta]

Hi ABx, I think what hop_goblin meant is a line at the joint that initially not exist prior to firing of the pot. I found one link, suggested by him at the Houdeblog. Check this out:
http://www.houdeasianart.com/index.php? ... cts_id=474
This line could also exist inner the pot, where another joints met.
I agree with you, it should have no benefit other than for authentification of the clay.
But as a newbie...hm...my opinion could possibly wrong.

[chrl42]

I beg to differ, what you meant is Huang Lung Shan Zhuni which is original zhuni and mountain where original zisha comes from and had gone decades ago. But yixing crafters been finding out other mountains where zisha still exists(if not as good as the original), so goes for zhuni.
As far as I know of, there is 2 more mountains that zhuni comes fron recent days.

Here is how you might distinguish original zhuni.
1. Zhuni shows 30% of shrinkage after being heated at 1200C from its original so it has very unique sound. Much higher tone than other zisha clay made teapot.
2. If teapot has wrinkled surface(also applies to high percent of shrinkage), it might gives more credit to its originality. However not every original zhuni teapot has wrinkled surfaces.
3. Zhuni is hardest clay to make into a teapot. If you look inside the teapot, you would realise it is molded rather roughly. Because zhuni masters can't shape up the teapot twice.
4.Never buy yixing ware that is as glossy as jade or teapot that rather looks a bit of 'mud' than zisha of its specific surface.

Zhuni is a clay that has highest numbers of fake ones. So even in China, it is hard to find real zhuni teapot at reasonable price. I won't mention numerous cheap yixing wares thats out on ebay worldwide of course.

[betta]

.Never buy yixing ware that is as glossy as jade

I heard glossy yixing wares are 'made' by mixing artificial colour (paint) and ox horn into the raw clay. Is that true?

[chrl42]

I heard glossy yixing wares are 'made' by mixing artificial colour (paint) and ox horn into the raw clay. Is that true?

I believe anyone who's seen real zisha teapot might distinguish artificial colored teapots from its specific zisha type.
Original zisha clay does very good job at drying out water quickly, but fake yixing ware the water never dries out.
By the way, even among yixing ware. Zhuni tends to exhibit rather glossy surface while clay such as qing sui ni shows very dried surface.
Never heard of ox horn, but there are ways to coat the teapot to make more pretty so it applies to more people especially in southern china.

[MarshalN]

HG -- the joint line does NOT have to be present for a pot to be zhuni. Rather, the joint line is sometimes a sign that it was a piece made purely by hand, rather than a mould or slipcast. HOWEVER, the joint line is VERY EASILY FAKED. So all in all, the joint line doesn't mean much of anything. I've seen many, many faked pots in Taiwan that have a joint line.

Also, joint lines are not unique to zhuni pots. Zisha pots also have jointlines. Modern pots also have jointlines too, except it is now common practice to smooth the surface out so that the joint line is not really visible to the naked eye. In fact, if you make any sort of pottery that is moulded, you're probably going to have jointlines.