An Artifact from Viet Nam

[Al Kowsky]

I spent the summer of 1967 to the summer of 1968 in Viet Nam with the U.S. Army. My first duty station was at Pleiku in the central highlands, & three months later I was transferred to a Dong Ba Thin, tiny outpost in southern Viet Nam. One of my jobs at that outpost was driving courier or riding as shotgun to several communication centers delivering classified information. On one trip we stopped at an outdoor market in the city of Nah Trang, where I spotted a vendor selling artifacts & knickknacks. The Chinese woman who had the display spoke excellent English told me the tea bowl I picked up was very old & she wanted $10.00 in American money for it. I knew intuitively the bowl was old as she did but neither of us knew anything more about it. I scoffed at the price 🤨, started walking away, & she asked what would you pay? I pulled a $5.00 bill from my pocket & she said OK. Many years later I learned the tea bowl was an early example of blue & white porcelain made at the Chu Dau kilns, circa AD 1450-1500 ☺️. The bowl has a degraded surface glaze from spending centuries in salt water, undoubtedly it was recovered from a shipwreck. During the reign of Emperor Le Thang Tung, AD 1460-1497, the Annamese had a flourishing export trade of pottery & porcelain to Japan & other countries in Southeast Asia. The blue color was achieved by using a paint mixed with cobalt. If the ceramic was over-fired the color would darken to nearly black, as is the case with my tea bowl 🙁. This artifact isn't worth much money, but it has great sentimental value to me. I often drink herbal tea from this bowl 😊. Pictured below are four different views of the bowl.

[John Conduitt]

Great story. And well done for not breaking it.

[Etcherdude]

How do you know the glaze contains cobalt. Cobalt is poisonous.

[Kamnaskires]

Beautiful. Some years back I had seriously considered picking up a piece or two salvaged from the 15th century Hoi An wreck. There were a number of them on the market at that time - quite similar (to yours) blue-and-white ware.

 

Thanks for sharing.

[John Conduitt]

38 minutes ago, Etcherdude said:

How do you know the glaze contains cobalt. Cobalt is poisonous.

It is, but even in higher doses not enough to cause much harm.

[Al Kowsky]

1 hour ago, Etcherdude said:

How do you know the glaze contains cobalt. Cobalt is poisonous.

I have never heard of anyone being poisoned by using blue & white porcelain 🤔. Countless millions of pieces have been made by Asian countries. Don't forget that the cobalt is under the glaze, & the glaze is actually a thin layer of glass. My tea bowl has a degraded surface but it hasn't been totally removed. It's also possible that the deleterious effect of the cobalt has been neutralized after being in a high-fired kiln. 

[Al Kowsky]

1 hour ago, Kamnaskires said:

Beautiful. Some years back I had seriously considered picking up a piece or two salvaged from the 15th century Hoi An wreck. There were a number of them on the market at that time - quite similar (to yours) blue-and-white ware.

 

Thanks for sharing.

The shipwreck you're referring to yielded 250,000 pieces of blue & white porcelain 😮! The National Museum in Hanoi kept the best pieces & the rest was offered for sale in 1985 😊. Prices on the shipwrecked pieces have dropped considerably since then, so you may want to take another look at what's being offered for sale 😉.

[Al Kowsky]

The Persians were the first ones to use cobalt for blue color in ceramics, & the Chinese began buying cobalt from the Persians over a thousand years ago. The Chinese blue & white porcelain from the Yuan & Ming dynasties is the most prized in the world, with single pieces selling for over $30,000,000.00 at auction 🙄! Chinese immigrants taught the Annamese how to make porcelain & the use of cobalt in the early 15th century.  Pictured below is a Chinese blue & white dish, about 6 in. dia. of very fine color in my collection. The underside has a 6 character reign mark identifying it as made in the imperial kilns during the reign of the Guangxu Emperor, AD 1875-1909.

[NewStyleKing]

Look everybody, when technically poisonous things are vitrified, as in porcelain glazes their solubility is neutralised  and solubility is the factor in poisonous ability , plus their intrinsic nastiness!  Arsenic is very common and highly toxic, but neutralised in clays  and glazes.....zilch!  Uranium....in glazes technically harmless except the radioactivity which is unaffected.  To stop spreading Radioactive liquids are vitrified. Still radioactive  but immobilised!

 

Maybe its me but but I think people worry too much about minor things!  Patinas, tones, pvc flips handling coins ( for god sakes-don't drop them or try to bend them!) be sensible ! Of, course when you magnify things you can find scratches, They are not quotidian boring USA Lincolns Washington quarters, dimes and nickels  or Kennedy half dollars!  Now the !Indian" stuff was a lot better...buffaloes Indian Heads  much much better! But bloody lincoln cents and montefiori nickels and Roosevelts dimes, forgive me but they are sh...!

 

NSK=John

Edited July 13, 2022 by NewStyleKing

[Etcherdude]

13 hours ago, Al Kowsky said:

The bowl has a degraded surface glaze from spending centuries in salt water, undoubtedly it was recovered from a shipwreck.

@NewStyleKing would you say Intact glazes are much better at isolating toxic matter than broken ones are?

Edited July 13, 2022 by Etcherdude

[NewStyleKing]

I would say that vitrification has taken place and cobalt has been chemically transformed in to complex silicates which are non soluble which are safe! the degraded surface is that degraded, rubbed, it's still a cobalt complex  as insoluble silicates! Mechanical rubbing is not going to break up complex molecules.

[Al Kowsky]

1 hour ago, Etcherdude said:

@NewStyleKing would you say Intact glazes are much better at isolating toxic matter than broken ones are?

I'm not a scientist, but I agree with John's (NSK) comment 😉. After being exposed to a high-fired kiln reaching temperatures in the range of 2,600-2,900 F, the cobalt now has a different structure & is no longer poisonous without regards to what remains on the surface of a porcelain object.