S Slatin on sun 31 aug 03
I can't tell you where the cobalt came from, but it's not related to
Lapis lazuli. Lapis lazuli is a rock, not a mineral, formed in
limestone
And with the color coming from the lazurite in it. Lazurite is (AFAIK)
Sodium Calcium Aluminum Silicate Sulfur Sulfate. You only call it lapis
Lazuli when the rock has flecks of pyrite in it.* Normally there's no
cobalt at all in it, though it is a rock, and could have anything.
LL has come from Afghanistan and Tajikistan since 4-5-6 thousand years
ago, so the Chinese a piddly 500 years ago probably knew where it came
from. I believe you can grind it up and use it as a coloring for the
natural paint 'ultramarine.'
* with no pyrite, it's called sodalite and is considered less valuable.
(all this schooling and no one ever asks the questions I'm ready for
...)
Steve S
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paul Lewing
Sent: Sunday, August 31, 2003 9:17 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Early cobalt
I've been doing some research lately into the beginnings of porcelain
manufacture and am curious about the cobalt that the Ming Dynasty
potters
were using to make all that blue and white stuff.
I've read that before they discovered their own supply of cobalt, they
were
getting it from the Middle East, probably through Persia over the Silk
Road.
Two kinds are mentioned a lot- Mesopotamian Blue and Somali Blue. I'm
wondering if the cobalt was really mined there or was it just bought
there
by the Chinese. I can easily see them calling it Somali Blue because
they
bought it from some Somali guy in Sultanabad or someplace.
I know that there are huge stocks of cobalt in central Africa,
particularly
eastern Congo. Is it possible that this cobalt was coming from Africa
through Somalia to Persia, being sent to China and used on pots, and
then
shipped back to Europe? And this as early as 1500 AD or so?
Also I'm wondering what form the cobalt was in, both when it was mined
and
when it was sold to the Chinese. Was there any processing involved?
My wife speculated that there's a lot of lapis lazuli in the Middle
East,
and maybe they were grinding that up. Is that possible? Is lapis
cobalt?
Actually, I've been wondering about a lot of the colorants we use in
this
context. Iron and copper are pretty widely distributed and easy to mine
and
process, but what about antimony, which was probably the next colorant
that
people started to use, and then manganese. Are there any books on this
subject? If Mimi Obstler's "Out of the Earth, Into the Fire" covered
colorants, it would be exactly what I had in mind.
Paul Lewing, Seattle
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Paul Herman on sun 31 aug 03
Hello Paul,
I always read your posts, and enjoy them.
Looks like Lapis Lazuli isn't a source of Cobalt. "Mineralogy" by
Sinkankas has the formula of Lazurite as (Na,Ca)4(SO4,S,Cl)(AlSiO4)2.
Yow!
Name: From ancient Persian "lazhuward", for Lapis Lazuli, containing
Lazurite as the principal mineral.
Chemistry: A complex sodium-calcium alumino-silicate, with sulfate,
sulfur, and chlorine appearing in various proportions.
I'll be interested to learn more about the old cobalt.
Best wishes,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: Paul Lewing
> My wife speculated that there's a lot of lapis lazuli in the Middle East,
> and maybe they were grinding that up. Is that possible? Is lapis cobalt?
Diane Winters on sun 31 aug 03
Hi Paul,
The research you're doing sounds fascinating.
There's a book out called "Colors: The Story of Dyes and Pigments" by
Delamare and Guineau (I heard Delamare interviewed on NPR). Don't know if
it has the info you're looking for but it's apparently a good and
interesting read. If you google the title you'll get lots of hits; here's
the URL to a brief review:
http://www.art-book-reviews.com/Colors_The_Story_of_Dyes_and_Pigments_081092
8728.html
At the bottom of that page are links to other books on the same/similar
subject with reviews. For instance, extremely mixed reviews on a book
called "Blue, the History of a Color" by Pastourear. Hope this helps.
Diane Winters
(who's tempted by so many interesting subjects awaiting time and pursuit
that, like Ulysses, I've got to plug up my ears with wax to avoid hearing
their siren songs.)
Paul Lewing on sun 31 aug 03
I've been doing some research lately into the beginnings of porcelain
manufacture and am curious about the cobalt that the Ming Dynasty potters
were using to make all that blue and white stuff.
I've read that before they discovered their own supply of cobalt, they were
getting it from the Middle East, probably through Persia over the Silk Road.
Two kinds are mentioned a lot- Mesopotamian Blue and Somali Blue. I'm
wondering if the cobalt was really mined there or was it just bought there
by the Chinese. I can easily see them calling it Somali Blue because they
bought it from some Somali guy in Sultanabad or someplace.
I know that there are huge stocks of cobalt in central Africa, particularly
eastern Congo. Is it possible that this cobalt was coming from Africa
through Somalia to Persia, being sent to China and used on pots, and then
shipped back to Europe? And this as early as 1500 AD or so?
Also I'm wondering what form the cobalt was in, both when it was mined and
when it was sold to the Chinese. Was there any processing involved?
My wife speculated that there's a lot of lapis lazuli in the Middle East,
and maybe they were grinding that up. Is that possible? Is lapis cobalt?
Actually, I've been wondering about a lot of the colorants we use in this
context. Iron and copper are pretty widely distributed and easy to mine and
process, but what about antimony, which was probably the next colorant that
people started to use, and then manganese. Are there any books on this
subject? If Mimi Obstler's "Out of the Earth, Into the Fire" covered
colorants, it would be exactly what I had in mind.
Paul Lewing, Seattle
steve harrison on mon 1 sep 03
Hi Paul,
Lapis is a combo of copper minerals with some calcite and pyrite.
Cobalt occurs naturally in many forms often associated with manganese.
Wad is a very common example, it is precipitated spring water that
flows through igneous rocks.
There is too much to answer here.
try "Rutley's elements of mineralogy"
or even my own book "Geology, rock glazes and mineral processing for
potters"
it has a little bit on the iron, manganese and cobalt that I have
fossicked for.
Best wishes
Steve Harrison
Hot & Sticky Pty Ltd
5 Railway Pde
Balmoral Village
NSW 2571
Australia
http://ian.currie.to/sh/Steve_Harrisons_books.html
> Was there any processing involved?
> My wife speculated that there's a lot of lapis lazuli in the Middle
> East,
> and maybe they were grinding that up. Is that possible? Is lapis
> cobalt?
> , and then manganese. Are there any books on this
> subject? If Mimi Obstler's "Out of the Earth, Into the Fire" covered
> colorants, it would be exactly what I had in mind.
> Paul Lewing, Seattle
Louis Katz on mon 1 sep 03
Somewhere some when I picked up the impression that early cobalt was
"mined" by picking up the pebbles in a river bed. I don't know what
mineral or where.
Louis
On Sunday, August 31, 2003, at 11:17 PM, Paul Lewing wrote:
> I've been doing some research lately into the beginnings of porcelain
> manufacture and am curious about the cobalt that the Ming Dynasty
> potters
> were using to make all that blue and white stuff.
> I've read that before they discovered their own supply of cobalt, they
> were
> getting it from the Middle East, probably through Persia over the Silk
> Road.
> Two kinds are mentioned a lot- Mesopotamian Blue and Somali Blue. I'm
> wondering if the cobalt was really mined there or was it just bought
> there
> by the Chinese. I can easily see them calling it Somali Blue because
> they
> bought it from some Somali guy in Sultanabad or someplace.
> I know that there are huge stocks of cobalt in central Africa,
> particularly
> eastern Congo. Is it possible that this cobalt was coming from Africa
> through Somalia to Persia, being sent to China and used on pots, and
> then
> shipped back to Europe? And this as early as 1500 AD or so?
> Also I'm wondering what form the cobalt was in, both when it was mined
> and
> when it was sold to the Chinese. Was there any processing involved?
> My wife speculated that there's a lot of lapis lazuli in the Middle
> East,
> and maybe they were grinding that up. Is that possible? Is lapis
> cobalt?
>
> Actually, I've been wondering about a lot of the colorants we use in
> this
> context. Iron and copper are pretty widely distributed and easy to
> mine and
> process, but what about antimony, which was probably the next colorant
> that
> people started to use, and then manganese. Are there any books on this
> subject? If Mimi Obstler's "Out of the Earth, Into the Fire" covered
> colorants, it would be exactly what I had in mind.
> Paul Lewing, Seattle
>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
Lori Leary on mon 1 sep 03
Paul,
There is a fascinating book, "Bright Earth: Art and the Invention of Color"
by Phillip Ball. It focuses mostly on pigment as it applies to painting.
Maybe not quite what you're looking for, but a worthwhile read.
Lori L.
lleary@epix.net
Mountain Top, Pa
Wood Jeanne on mon 1 sep 03
Hi Paul,
Research on early pottery is a hobby of mine, you
raise some interesting questions
Cipriano Piccolopasso's Books: "The Three Books of the
Potter's Art". Has some information on minerals used
in some 15th Century Italian Maiolica glazes, but, I
don't think he reports where they were mined. He does
report the use of lapis lazuli for glaze, an an impure
form of cobalt called "Zaffre" among other minerals.
Good luck,
Jeanne W.
--- Paul Lewing wrote:
> I've been doing some research lately into the
> beginnings of porcelain
> manufacture and am curious about the cobalt that the
> Ming Dynasty potters
> were using to make all that blue and white stuff.
> I've read that before they discovered their own
> supply of cobalt, they were
> getting it from the Middle East, probably through
> Persia over the Silk Road.
> Two kinds are mentioned a lot- Mesopotamian Blue and
> Somali Blue. I'm
> wondering if the cobalt was really mined there or
> was it just bought there
> by the Chinese. I can easily see them calling it
> Somali Blue because they
> bought it from some Somali guy in Sultanabad or
> someplace.
> I know that there are huge stocks of cobalt in
> central Africa, particularly
> eastern Congo. Is it possible that this cobalt was
> coming from Africa
> through Somalia to Persia, being sent to China and
> used on pots, and then
> shipped back to Europe? And this as early as 1500
> AD or so?
> Also I'm wondering what form the cobalt was in, both
> when it was mined and
> when it was sold to the Chinese. Was there any
> processing involved?
> My wife speculated that there's a lot of lapis
> lazuli in the Middle East,
> and maybe they were grinding that up. Is that
> possible? Is lapis cobalt?
>
> Actually, I've been wondering about a lot of the
> colorants we use in this
> context. Iron and copper are pretty widely
> distributed and easy to mine and
> process, but what about antimony, which was probably
> the next colorant that
> people started to use, and then manganese. Are
> there any books on this
> subject? If Mimi Obstler's "Out of the Earth, Into
> the Fire" covered
> colorants, it would be exactly what I had in mind.
> Paul Lewing, Seattle
>
>
__________________________________
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Snail Scott on mon 1 sep 03
At 08:17 PM 8/31/03 -0800, you wrote:
>Is it possible that this cobalt was coming from Africa
>through Somalia to Persia, being sent to China and used on pots, and then
>shipped back to Europe? And this as early as 1500 AD or so?
Trade routes in this period were amazing - stuff going
from everywhere to everywhere. Slow, and expensive, but
it got there, across thousands of miles on what we would
not even call a road. Vast quanitities of goods!
Typically, one merchant would not make the whole trip
from (for instance) Africa to China. They worked 'legs'
of the route - their local segment - then sold the cargo
to a merchant who worked the next leg of the trade route,
and so on.
So, it's very possible that African cobalt was being
sold in China. It's also likely that it was mined in (or
refined to) a fairly pure form, (though not 'ceramic
grade') to keep transport costs down. It's also likely
that the end buyer wouldn't necessarily know the precise
origins of the product.
And yes, lapis lazuli has cobalt in it.
-Snail
Snail Scott on mon 1 sep 03
D'oh!
I just wrote that lapis is cobalt; it ain't.
(That's what I get for 'remembering' my
mineralogy instead of checking. Sorry.)
-Snail
Paul Lewing on mon 1 sep 03
on 9/1/03 7:48 AM, Snail Scott at snail@MINDSPRING.COM wrote:
> Typically, one merchant would not make the whole trip
> from (for instance) Africa to China. They worked 'legs'
> of the route - their local segment - then sold the cargo
> to a merchant who worked the next leg of the trade route,
> and so on.
Having been a mule packer in my younger days, I can sure relate to this.
makes me wonder how many canyons from Egypt to Afghanistan have a
hundred-pound pile of cobalt amid a heap of horse bones, the remains of what
we used to refer to as "a real good donkey wreck".
Paul Lewing, Seattle
Paul Lewing on tue 2 sep 03
I asked my question about where cobalt came from to Pamela Vandiver at the
Smithsonian Institution. Some of you may remember her mind-boggling Glaze
Doctor presentation at NCECA three years ago with Ian Currie. Here's what
she said:
"Somali is probably Omani, as the Omani were great traders from the 12 and
perhaps 10 centuries along the Indian Ocean coasts. Cobalt underglaze
decoration on whole vessels has been found on a wreck in Indonesia from the
Tang dynasty, as well as on some sherds from Yangzhou, near Nanjing, China,
at hte southern end of the Grand Canal. Chinese Glazes by Nigel Wood, or
Needham volume on ceramics in China, forthcoming, Cambridge Univ. Press by
Rose Kerr, et al.
Alex Kaczmarczyk has published a 15th C B.C. way of getting cobalt from a
cobalt-aluminum spinel in the Amarna period in Egypt as a colorant for
glass. Badakshan in Afghanistan is the other well known source, and James
Watt in Ars Orientalia, vol. 11, published lots of info on cobalt in China.
The last Shanghai Inst. of Cera. publication had an excellent article on
trade element analysis of cobalt on Chinese ceramics."
So there you go.
Paul Lewing, Seattle
Diana Pancioli on tue 2 sep 03
Hi Paul:
Everything I have read about Islamic Ceramics says that
early Cobalt had its origins in Persia.
I haven't heard mention of Africa. I haven't read
everything there is to read, but quite a bit.
Diana
steve harrison on tue 2 sep 03
Louis,
I believe that you might be referring to Bernard Leach's "A Potters
Book" where he talks about gosu on page 129.
Best wishes
Steve Harrison
Hot & Sticky Pty Ltd
5 Railway Pde
Balmoral Village
NSW 2571
Australia
http://ian.currie.to/sh/Steve_Harrisons_books.html
On Monday, September 1, 2003, at 11:48 PM, Louis Katz wrote:
> Somewhere some when I picked up the impression that early cobalt was
> "mined" by picking up the pebbles in a river bed. I don't know what
> mineral or where.
> Louis
> On Sunday, August 31, 2003, at 11:17 PM, Paul Lewing wrote:
MarjB on tue 2 sep 03
Morning Paul - I asked a retired geologist your question and one of his =
books Dana's Textbook of Mineralogy ISBN 0 471 19305 4 has one entry =
that I thought might be a clue: Cobaltite - found in =
Dashkesan,Azerbaijan,TransCaucasia. Also Sweden,Norway,Cornwall and =
Cobalt, Ontario.
Composition: Sulpharsenide of cobalt. CoAsS or CoS2 .CoAs2 equals =
Sulphur 19.3 - arsenic 45.2 - cobalt 35.5 .
Possibly the first three might be the source. I have found a great new =
book to puruse. MarjB
John Britt on tue 2 sep 03
Paul,
Much of the early cobalt was imported from Persia and it was very hard to
get and quite expensive. The Chinese finally found a source of cobalt from
the mineral Asbolite. This cobalt ore contained iron, manganese and
cobalt. (It was also known as cobalt ochre and contained 30 =96 40% cobalt.)=
The Chinese also combined the Persian cobalt with the Chinese ore in a
ratio of 3 to 2. This mixture produced a blue known as Mohammedan blue or
Sumatran blue. (In Japan this cobalt ore is know as Gosu. It is mixed with
green tea to aid in smoothness of application.) It was then painted
directly on the green ware. Afterwards, it was covered with a thin coat of
clear glaze and fired to produce the blue and white ware of the 14th and
15 century.
John Britt
Jennifer F Boyer on wed 3 sep 03
Hi All,
In a book on Tin Glazed Pottery by Alan Caiger Smith, he says
that the first signs of regularly produced decorated pottery
were in the Middle East in Mesopotamia in the 9th century. He
says the Arabs were travelers, and that trade in pottery grew in
both directions between China and the Middle East. He says that
in the area of Bagdad in the 9th century pots of the Tang
dynasty of China were present and admired.
They influenced what was made in Bagdad. BUT he says that the
first use of cobalt was in this area of Bagdad and came to be
known as Mahomedan Blue. The Chinese were inspired to use cobalt
from the Islamic pottery imported to China.....
Jennifer
Diana Pancioli wrote:
> Hi Paul:
>
> Everything I have read about Islamic Ceramics says that
> early Cobalt had its origins in Persia.
>
> I haven't heard mention of Africa. I haven't read
> everything there is to read, but quite a bit.
>
> Diana
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
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http://www.thistlehillpottery.com/
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