Ok, so reading through the thread about finding Zhuni clay, I'm really curious what the desire for it is.
I'm also really curious why the attraction for Zhuni in particular. Wikipedia says that Zhuni is translated as "cinnabar clay" and that the clay sometimes has the bright red hue of cinnabar. Does Zhuni clay actually contain cinnabar? If it did that would greatly greatly concern me.
Cinnabar is a natural form of mercury as HgS. Cinnabar when mined has its mercury extracted by use of heat and blowing air over it for the reaction of HgS + 02 -> Hg + SO2. Which would mean in a warm environment you will be producing both S02 (sulfur dioxide, the smell of rotten eggs) and elemental mercury, which then oxidizes into HgO, aka Mercury(II) Oxide, which is the form of mercury that you worry about consuming in fish, meats, etc. It builds up in certain tissues in the body and has a ill neurological effects.
So i'm really curious of the term zhuni clay as cinnabar clay is just in name/color only, or if there really in cinnabar in the stuff. And also why is it so sought after?
First of all, among zisha clay zhuni is rarest of all. Zisha clay has a layer. On top of it is zini, hongni and something like that and zhuni or other sought-after clay usually exist on the bottom. There are zini(purple clay), hongni(red clay), liuni(green clay), heini(black clay) and much,much more..those are kind of clay that comes from Jiangsu province and nowhere else, and said to be best type of pot for tea brewing for centuries in China.
Second of all, zhuni is said to have prettiest color and gloss to some cult of yixing teapot followers. As time goes by, real zhuni pot will exhibit beautiful reddish presence which makes people happy just by looking at it.
Third of all, zhuni is clay which is hardest to make into a teapot. Most unskilled teapot crafters won't even think about trying it, and even among skilled crafters 4 out of 10 times teapot will just be cracked while heating procedure. And because of its 30% of shrinkage, it requires a master to understand before-and-after of its shape which is hard subject for yixing crafters.
As for tea brewing, I don't know if zhuni is idle. Zhuni is a clay that absorbs little or none of tea aroma and it is said to brew type of tea with strong aroma, such as Tieguanyin or other light fermented oolong tea. It is known each clay has its best partner when brewing and is related to time of evaporation.
Second of all, zhuni is said to have prettiest color and gloss to some cult of yixing teapot followers. As time goes by, real zhuni pot will exhibit beautiful reddish presence which makes people happy just by looking at it.
Third of all, zhuni is clay which is hardest to make into a teapot. Most unskilled teapot crafters won't even think about trying it, and even among skilled crafters 4 out of 10 times teapot will just be cracked while heating procedure. And because of its 30% of shrinkage, it requires a master to understand before-and-after of its shape which is hard subject for yixing crafters.
As for tea brewing, I don't know if zhuni is idle. Zhuni is a clay that absorbs little or none of tea aroma and it is said to brew type of tea with strong aroma, such as Tieguanyin or other light fermented oolong tea. It is known each clay has its best partner when brewing and is related to time of evaporation.
Last edited by chrl42 on Mar 27th, '08, 06:51, edited 1 time in total.
Chrl42 is right, the colour of zhuni resembles cinnabar, that's the main reason.
Pentox, I supposed you're a chemist too, so by reading the MSDS of cinnabar, I believe you will understand it.
In fact the red color comes from the high content of iron (Fe) which is completely oxidized up to its highest oxidation level, Fe3+, in the form of Fe2O3 in a firing process which also has similar brown to reddish colour. That's the reason why true zhuni is denser than zini or other yixing clay. If you check the MSDS of Iron oxide, then you'll know why I'm still alive
Pentox, I supposed you're a chemist too, so by reading the MSDS of cinnabar, I believe you will understand it.
In fact the red color comes from the high content of iron (Fe) which is completely oxidized up to its highest oxidation level, Fe3+, in the form of Fe2O3 in a firing process which also has similar brown to reddish colour. That's the reason why true zhuni is denser than zini or other yixing clay. If you check the MSDS of Iron oxide, then you'll know why I'm still alive
Ah, it's all so much clearer now. I had figured that the cinnabar naming was just due to color, but I wasn't sure. I thought it would be a bit odd for cinnabar to end up in a clay material as well naturally.
It also makes a lot more sense now why someone would pay that much for a zhuni pot in comparison to a much cheaper pot.
thanks guys!
It also makes a lot more sense now why someone would pay that much for a zhuni pot in comparison to a much cheaper pot.
thanks guys!