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Pottery/Firing Faults


Star crack
Star crack  

Rim inside and base
Rim inside and base  
I have got a large chinese vase with Qianlong seal mark, it is 54cm in height. The painting is very unusual but extremely delicate. The glaze is not shiny, more dull. At the bottom inside the vase there is a large star crack. It is filled with some kind of clay and covered with paint - the paint peels of now. This star crack is only inside, it does not show at the base, but at the base there seems to be another crack near the rim which looks like some kind of warping. It is under the glaze. Because of these massive firing faults beeing on such an elaborately painted vase I would think that this vase simply has to be very old. I think it has to be made in times when technology and knowledge weren't developed enough to ensure production without the possibility of destroying the whole piece. Or am I wrong and this could also be a modern fake, perhaps just a few years old? Is it possible to make firing faults on purpose, without the risk of loosing the piece? And... please take a look at the material, is a composition like this usual / suitable for a high quality modern (fake) vase? I would of course send you photos of the whole vase too, but here I can only upload 2 images.  

Thank you very much for your help!

Dear Angela,

Thank you for your recent questions. As for the vase and identifying it's authenticity by faults can not qualify it to be of a particular make or historical period. However, the mark on the bottom of the vase is a clear indication as to the time frame of when the vase was made. If you could send me a photo of the seal mark, I will gladly research the mark for you from my historical records and let you know the authenticity of the vase. I would also love to see a photo of the painting of the vase if at all possible.

By the way, faults in old pottery pieces do not indicate lack of knowledge or technology as faults can occur in some of the most highly technical kilns and with some of the most prestigious potters. In the case of this piece, the star mark at the bottom of the pot is most likely not a fault but rather a compression relief to prevent the bottom from cracking during drying and the initial heating of the kiln. Also, warping can be caused by drying too quickly or firing too fast, and in this case, if the piece is not of period, but rather mass production, warping is seen more often than not.

I look forward to your reply so I can identify your piece.

Ms. Ti Phillips
Earth Stoke 'N Fire Pottery Studio and Artist Retreat


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Ti Phillips


Will answer any questions on hand building, wheel, glaze, firing. Speciality questions to include those in glaze calculation and development, firing techniques. Please do not send questions on identifying pottery. Although I would love to add this to my question topics, I have a retreat to run as well as the studio and volunteering on AllExperts, and therefore do not have the available time to research indentification and marks. Thank you for understanding.


Experience includes 30 years in pottery design and education. Have taught online and studio classes worldwide for the last 20 years. Own a pottery retreat specializing in firing techniques. Have 12 years solid experience in glaze calculation and formulation as well as problem solving in glaze chemistry. I am the first potter in the United States to have developed a complete package of pottery equipment blueprints for a studio. The blueprints include wheels, kilns, studio furniture, wedgeboards, raku kilns, slab rollers, ball mills and studio tools.

Alliance of Pottery Artists Worldwide Association

Ceramic Industry - PPP Wyndstryder Press - Pottery Journal

University of Sciences and Art's of Oklahoma, studied under Professor Jaymes Dudding.

Awards and Honors
Potter of the year with APAWA, various awards for showmanship and design.

Past/Present Clients
Available upon request.

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