Don Goodrich on wed 20 sep 06
Hey, all you native materials users.
I took the dog for a walk along the Lake Michigan beach
Sunday morning, and noticed an area of black sand.
Intrigued, I put a handful of the sand in a plastic bag
(gotta take bags along when you walk the dog) and brought it home.
Almost all the sand passed easily through an 80-mesh sieve.
Some of it would follow a magnet around when sprinkled on paper,
but some would not. Under 30X magnification, the individual grains
look like tiny rounded black beach pebbles, or pea gravel,
each grain between .003" - .005" (.07-.13mm) across.
No crystal facets appear, although the grains are shiny in sunlight.
Last night, I mixed up a small amount of test glaze using
50% gerstley borate, 20% EPK, and 30% black sand,
put it on a porcelain test tile and fired to cone 6
in the small test kiln (about 4 hours).
With it was a small shard of porcelain with unmixed black sand on it.
This morning I have a tile that appears shiny black.
In direct sunlight this changes to dark brown among patches of black,
with lighter brown in thin areas. The pattern resembles a very dark
temmoku. The raw fired sand remained granular and did not fuse
nor stick to the shard, and now no longer responds to a magnet.
Under magnification the glaze matix appears to consist of brown puddles
with clusters of black grains among them. No crazing has appeared yet.
The test tile was fired flat, so I can't be sure how runny this
would be. Given the base glaze, it would likely be runny, but might
make for some interesting effects.
Can any of you give me a clue as to what this black sand is?
Should I collect buckets of it, ignore it,
or avoid it like plague?
Suggestions, catcalls, bulk orders?
Cheers,
Don Goodrich
Steve Slatin on wed 20 sep 06
Don --
Taconite/magnetite? Lots of that stuff around Lake Mi.
The 50/30/20 glaze would be a great stable glaze with
the 20 being silica; taconite is mostly silica, IIRC.
-- Steve S
Don Goodrich wrote:
Hey, all you native materials users.
I took the dog for a walk along the Lake Michigan beach
Sunday morning, and noticed an area of black sand.
Intrigued, I put a handful of the sand in a plastic bag
(gotta take bags along when you walk the dog) and brought it home.
Almost all the sand passed easily through an 80-mesh sieve.
Some of it would follow a magnet around when sprinkled on paper,
but some would not. Under 30X magnification, the individual grains
look like tiny rounded black beach pebbles, or pea gravel,
each grain between .003" - .005" (.07-.13mm) across.
No crystal facets appear, although the grains are shiny in sunlight.
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John and Judy Hesselberth on wed 20 sep 06
On Sep 20, 2006, at 10:17 AM, Don Goodrich wrote:
> Can any of you give me a clue as to what this black sand is?
> Should I collect buckets of it, ignore it,
> or avoid it like plague?
Hi Don,
Black sand is common on a lot of beaches, but it comes and goes
rather quickly sometimes. I got a bucket of it last summer on the
Delaware Bay, but it was gone a couple days later and I have only
seen a hint of it since. As to what it is check out
http://geology.wr.usgs.gov/parks/coast/sand/blacksand.html or
http://en.wikipedia.org/wiki/Black_sand
So if you want more, better get out their quickly.
Regards,
John
Bonnie Staffel on thu 21 sep 06
Hey, Don,
You have just duplicated your find on Lake Michigan beaches as I did
probably 40 years ago. I was so excited and found a jug to gather it =
in.
Yes, it is magnetic, and my theory is that it is iron. =20
I used it to produce black speckles in my clay body when I had a gas =
kiln.
Never thought about using it for or in a glaze. I didn't know a lot =
about
clay things at that time. One of the problems this addition did to my
finished pieces was to cause the edges to shiver. After much research =
was
told to lower the glaze top temperature by one cone. That solved the
problem. Still had the specks besides having a beautiful glaze. I used
Rhodes 32 a lot back then as well as Carlton Ball's colored glazes for
reduction firing. =20
There was nothing better that I loved in reduction glazes than what we
called "potter's brown" at the time. But I also loved color so used the
oxides to good advantage along with the nice softening of the iron =
speckles.
All this information is my opinion from what I did years ago. I have no
scientific research to back this up. What happens to the magnetized =
bits of
iron is that the ions get saturated with the positive electrons to the
extent that they then repel each other. I tested this with a hand held
magnet. Now is there any other metal that is able to be attracted to a
magnet? If so, then this material could be another metal or a mixture =
of
metals. =20
Sounds like a good research job for you, Don.
Cheers, Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD Throwing with Coils and Slabs
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Charter Member Potters Council
sacredclay on thu 21 sep 06
This is facinating and even more so when I come across people that
can answer questions like these. I wonder if a galze recipe can be
made out of this and what will it look like. but of course, my
formost thought is, is it poisonous and will it leach into
food/drink? Kathryn --- In clayart@yahoogroups.com, John and Judy
Hesselberth wrote:
>
> On Sep 20, 2006, at 10:17 AM, Don Goodrich wrote:
>
> > Can any of you give me a clue as to what this black sand is?
> > Should I collect buckets of it, ignore it,
> > or avoid it like plague?
>
> Hi Don,
>
> Black sand is common on a lot of beaches, but it comes and goes
> rather quickly sometimes. I got a bucket of it last summer on the
> Delaware Bay, but it was gone a couple days later and I have only
> seen a hint of it since. As to what it is check out
>
> http://geology.wr.usgs.gov/parks/coast/sand/blacksand.html or
>
> http://en.wikipedia.org/wiki/Black_sand
>
> So if you want more, better get out their quickly.
>
> Regards,
>
> John
>
>
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John and Judy Hesselberth on thu 21 sep 06
On Sep 21, 2006, at 8:32 AM, sacredclay wrote:
> I wonder if a galze recipe can be
> made out of this and what will it look like. but of course, my
> formost thought is, is it poisonous and will it leach into
> food/drink?
Hi Kathryn,
Sure it can be used in glazes or clay bodies. Will it leach something =20=
terrible into food or drink--probably not because it is mostly iron =20
and silica. But nobody knows for sure unless they have tested the =20
resulting pottery. I use it in a way I don't have to worry about it. =20=
Take a spare salt shaker (or buy one for 79=A2 at Wal-Mart -- uh oh I =20=
hope I didn't just restart that thread again) and fill it with black =20
sand. Then sprinkle some on the outside of your freshly glazed pots =20
while they are still wet. Go easy--a little bit can add a nice =20
accent; a lot can result in a rough unpleasant-to-touch surface.
For those who live and sell their pots near the beach where they =20
collected the sand you can not only use it as a decorative accent but =20=
as a selling aid. Tell the visitors they are taking a bit of the =20
beach home with them.
Regards,
John=
Nancy Braches on thu 21 sep 06
I saw the black sand beaches on Maui....they were beautiful. Someone told me it was sand from the lava but I don't know for sure....will be interesting to find the answer
Nancy
Hilltop Pottery
John and Judy Hesselberth wrote: On Sep 20, 2006, at 10:17 AM, Don Goodrich wrote:
> Can any of you give me a clue as to what this black sand is?
> Should I collect buckets of it, ignore it,
> or avoid it like plague?
Hi Don,
Black sand is common on a lot of beaches, but it comes and goes
rather quickly sometimes. I got a bucket of it last summer on the
Delaware Bay, but it was gone a couple days later and I have only
seen a hint of it since. As to what it is check out
http://geology.wr.usgs.gov/parks/coast/sand/blacksand.html or
http://en.wikipedia.org/wiki/Black_sand
So if you want more, better get out their quickly.
Regards,
John
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Ivor and Olive Lewis on fri 22 sep 06
From memory, Mel the Mayor has mentioned the Great Lakes Black sands. I =
recall these were from the dross or slag created when smelting Iron, =
perhaps in the Duluth region.
There are other black sands. In Oz there are Ilmenite sands along the =
east coast. In the UK there are black sands along the Durham coastline, =
That's Coal. In other places it can be Mussel shell residues.
If you find something interesting do a few tests.
Best regards,
Ivor
Claudia MacPhee on fri 22 sep 06
Hi All, Black sands are really easy to get with the help of a gold pan. If you are lucky you might also get some gold...We have had our black sand assayed, mostly magnetite, hemetite, titanium and some trace minerals. It would vary according to source. Even if it isn't visable you can still find it easily enough most places. It is a by-product of placer mining. Fun stuff to play around with.
Claudia MacPhee, Tagish, Yukon
Don Goodrich on mon 25 sep 06
Hi folks,
Thanks for all your observations and opinions about black
sand. For now I'll go with the taconite/magnetite theory,
considering the location. It's also worth considering the
regional shipping. Countless ships have passed this shore
in the past century or so, moving minerals from the mines of Minnesota
and Wisconsin to the mills of Indiana. No telling what wrecks or
spills the currents and waves might bring to or from these beaches.
It was good to hear from Michael Banks, who=92s trove of
knowledge has been missing from this list for four years.
Thanks, Maggie!
No doubt I=92ll find some ues for the stuff before long. I hope
to do a Currie-type grid with it in a few days, and might
find something that looks intriguing. Might try it in some clay,
too, in case there=92s a need for speckles.
Meanwhile, it seems that the sand heats up only slightly after a minute in
the microwave oven. Hotter than the glass dish it was in, but not too hot
to touch. By contrast, the test tile glazed with it heats up a LOT in a
minute; even more than the cup of water sitting alongside it in the
microwave. Guess I=92d better not glaze any coffee mugs with this stuff!
I took the dog for a walk along the beach yesterday evening,
ready to collect more black sand. Although the sky was clear
and calm, large waves swept the shore and things had changed.
John H. was right: black sands can be transient.
There have been storms this past week.
The long stretch of black sand we'd walked on a week ago
has dwindled to a much smaller patch. Whether most has been
washed away or covered up is not obvious. I bagged about
five kilos of the sand and we left, which pleased the dog
who had been quite anxious about those waves.
Cheers,
Don Goodrich in cool but sunny Zion, Illinois
goodrichdn@aol.com
http://dongoodrichpottery.com/
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