Yixing

[faj]

Some, but not as many as on this one... actually only saw that many on lower quality Zisha.

I would be curious to understand what you consider "impurities". Would it be the black dots? Something else?

[DailyTX]

Some, but not as many as on this one... actually only saw that many on lower quality Zisha.

I would be curious to understand what you consider "impurities". Would it be the black dots? Something else?

Typically, impurities are other minerals found in zisha clay. Black dots are typically iron after firing. To get a better look at impurities in clay, you can try to find some high quality resolution photos of duan ni pot. You will see black, red, pale, yellow, and other minerals on the surface after the pot is fired, assuming the pot has not been dyed or processed with chemicals.

[faj]

Typically, impurities are other minerals found in zisha clay.

"Other minerals"... Other than what? For instance, my understanding is iron and mica are normal constituents of clay. Maybe too many iron dots would indicate issues, but would that made iron an impurity?

Or do you, by "impurities" mean, specks that are visible to the naked eye rather than blended in the general background color, whether they are made of minerals that are expected to be found in the clay or not?

[DailyTX]

Typically, impurities are other minerals found in zisha clay.

"Other minerals"... Other than what? For instance, my understanding is iron and mica are normal constituents of clay. Maybe too many iron dots would indicate issues, but would that made iron an impurity?

Or do you, by "impurities" mean, specks that are visible to the naked eye rather than blended in the general background color, whether they are made of minerals that are expected to be found in the clay or not?

My understanding is that impurities refer to specks/dots that are visible to the naked eye. Now, you asked about blended clay. Duan ni is a blended clay by nature, that’s why Duan ni clay in high resolution would be a good reference to looking at impurities.

[.m.]

"Other minerals"... Other than what? For instance, my understanding is iron and mica are normal constituents of clay. Maybe too many iron dots would indicate issues, but would that made iron an impurity?

Or do you, by "impurities" mean, specks that are visible to the naked eye rather than blended in the general background color, whether they are made of minerals that are expected to be found in the clay or not?

Both mica specks and molten iron spots are considered undesirable, and, i think, part of the weathering and aging process is not only to increase plasticity but also to get rid of these. It's not the minerals that are "impurities" in this case, but the spots they can create.

[faj]

Both mica specks and molten iron spots are considered undesirable

Is that for aesthetic reasons, or for reasons having to do with any effect on tea?

[Youzi]

Impurities are basically stuff that doesn't look good.

You should think about like this, the perfect teapot has:
- Perfectly uniform and smooth surface
- The color is the same everywhere
- Texture is like Jade
- Has a nice shine
- (geometric requirements, etc.)

These were signs of a quality teapot back in the day, when making such a teapot was difficult.
Now the above description basically refers to 300 rmb fake yixing. Made from kaolin, added with iron oxide and made into 200 mesh.

Naturally there is and was an iron removing process, or at least sieving where the bigger particles are removed, so they don't cause "impurities/faults".
The teapot I linked hasn't gone through any impurity removal process and besides that was also over fired, hence the many "impurities" on it.

Btw, zhuni cannot be weathered.

Both mica specks and molten iron spots are considered undesirable

Is that for aesthetic reasons, or for reasons having to do with any effect on tea?

purely aesthetics, most stuff about yixing has nothing to do with optimizing tea brewing capabilities.

[OCTO]

Interesting to see so much impurities on a zhuni pot close up. I wonder for people who own antique zhuni pots can comment if you noticed impurities on yours pots?

Some, but not as many as on this one... actually only saw that many on lower quality Zisha.

+1

[OCTO]

Some, but not as many as on this one... actually only saw that many on lower quality Zisha.

I would be curious to understand what you consider "impurities". Would it be the black dots? Something else?

Typically, impurities are other minerals found in zisha clay. Black dots are typically iron after firing. To get a better look at impurities in clay, you can try to find some high quality resolution photos of duan ni pot. You will see black, red, pale, yellow, and other minerals on the surface after the pot is fired, assuming the pot has not been dyed or processed with chemicals.

Agree with @DailyTX... I would also like to add, old / antique teapots are plagued with impurities as the filtering process is not as advanced as what you get in modern days. Therefore, if a vendor is trying to sell me an old / antique pure clay teapot... be it any clay.... that's would be a HUGE red flag for me. Try magnifying an antique teapot and observe the result. You don't need a microscope... a simple 30X magnifier used by jewellers are more than sufficient.

my 2 cents... cheers!!

[OCTO]

Both mica specks and molten iron spots are considered undesirable

Is that for aesthetic reasons, or for reasons having to do with any effect on tea?

purely aesthetics, most stuff about yixing has nothing to do with optimizing tea brewing capabilities.

@Youzi

Can you elaborate further on this???

Cheers!

[Youzi]

Is that for aesthetic reasons, or for reasons having to do with any effect on tea?

purely aesthetics, most stuff about yixing has nothing to do with optimizing tea brewing capabilities.

Youzi

Can you elaborate further on this???

Cheers!

I mean Zisha was found generally good for making tea, then it became more of an art for the scholars of china to show off to each other. Of course it should make nice tea. But that's not the main focus.

Maybe commoner pots are different? Ok don't know about those, because history usually mentions pots made by masters.

Of course there's overboard stuff, like highly artistic pots, which are unusable to make tea.

Like that bridge teapot and stuff like that. Pretty, but not practical.

[Mark-S]

I think that's a reproduction, but I am not 100% sure... Does this shape look a bit weird to you too? Unfortunately, I cannot get better pictures.

[.m.]

I think that's a reproduction, but I am not 100% sure... Does this shape look a bit weird to you too? Unfortunately, I cannot get better pictures.

Yes, it looks weird. Very clunky. And the carving is stiff.

[Mark-S]

@.m.

Okay, thanks I have still some trouble recognizing these standard F1 pots, because it's normal that the craftsmanship is not that good, and the photography skills of some sellers really suck. However, this pot seemed a bit too unproportional to me to be genuine.

-

I have bought this much nicer set recently. Seems to be genuine in my opinion... maybe late 70s to early 80s (?), but I will post it in the Facebook group once it arrives.

[Chadrinkincat]

@Mark-S
Overall shape of this pot doesn’t look right for F1. The shape of handle and placement seems especially wonky.