Black speckles in porcelain - sand?

[emma_19]

Hello, I wonder if anyone can help? 

I am intrigued by Kiho Kang's work. I met him recently at a ceramics fair and he said he uses sand in small increments to get the subtle black flecks in his porcelain. I wish I'd have asked him what he means by 'sand' - can anyone suggest what he might add to his clay to give it the black speckle? Black sand? Where would I find this?  Most grog I see tends to be light coloured? His work is often un-glazed so it is not something created by the effect of a glaze.

Here is an example of his work: https://www.maudandmabel.com/products/kiho-kang-small-container-with-lid

I would appreciate any ideas. Thanks!

Emma 

[Callie Beller Diesel]

I'm not sure what kind of material this might be, other than some kind of fine beach sand. It looks like it has a very fine texture, whatever it is, and the black is probably from small quantities of iron or other impurities. 

If you wanted to use grog, I've seen one guy make his own grog with coloured clay (eg with mason stains). Figuring out how to grind it that fine could prove interesting, though. 

[Tyler Miller]

The black speckle is an iron/manganese containing mineral of some kind.  It does look very fine.

Jonathan Walburg  out of Wisconsin does a similar thing with lake Superior beach sand in porcelain.   It’s a coarser effect, but he directly wedges sand into his porcelain.   He’s a pretty good guy to talk to if you track down his pottery page on facebook.  J pottery, I think.  

[Min]

Could try asking him via his contact page. http://kangkiho.com/?page_id=6  Maybe from a German supplier?

[hantremmer]

Could it be something like the ‘mica’ in this Japanese video?

 

 

[Magnolia Mud Research]

I have done the same thing, except I use the red sandy clay from the bottom of my Texas ponds (or from the bank of the pond when the pond is full). Dry the clay/sand; then crush the dried stuff with a mallet, and screen through a kitchen strainer.  Throw the big lumps back in the pond and use the fines.  Wedge into wet porcelain using slam-cut wedging technique and have a go.  I add some where between 1 or 2 cups of dry clay/sand  into a block of porcelain that is about 4x4x8 inches. 

 

If you don't have a pond, use the red sand from you nearby garden supply center.  

LT

[Bryan Johnson]

Try running a magnet through the beach sand.  If you get little black particles they will work.

[BlackDogPottery]

If you don't absolutely have to use sand. You can get Manganese in different mesh sizes. 20-40 mesh is similar to what I've seen in his work, plus it's still noticeable even without glaze and 60-80 mesh is a little finer. About 0.7% is all you would need for a heavy speckle but anything more than that you'll notice some bloating at ^6.  I got mine at The Ceramic Shop for $3.00 a pound which will go a really long way. 

[yappystudent]

This answers a question I was going to post about wedging some local Oregon beach sand into my clay, slips and whatnot. TY, now I will do so freely. 

[emma_19]

Thanks everyone for your very informative replies!