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Asbestos in Vermiculite

Please check what I found on the Internet regarding Vermiculite,
which a lot of European jewelers use as a cheap soldering base. When
I was trained in Germany, it was the only thing we had, everybody
used it everywhere…

Edith Schneider Jewelry
P.O.Box 52001
Palo Alto, CA 94303
(650) 813 9755

Oh no, not this again. It has been proven that vermiculite contains
no asbestos. There was a mine where some of the miners were exposed
to asbestos, but it was never traced back to the product they were
mining. Doing a search “vermiculite” may garner some good info.

    It has been proven that vermiculite contains no asbestos.
There was a mine where some of the miners were exposed to 
asbestos, but it was never traced back to the product they were
mining. Doing a search "vermiculite" may garner some good info. 

I beg to differ. If you search for vermiculite and asbestos in
google you get a whole bunch of hits about the Libby, Montana mine.
The asbestos was in with the vermiculite and not only were the miners
exposed, so were the workers in the plant that heated and expanded
the vermiculite for use as insulation, and families of the miners and
insulation plant employees. The mine was in operation from 1924 to
1990. I think the site is now a Superfund clean up.

There is also about a mine in Loisa, Virginia. It does
appear that in some instances vermiculite and asbestos are found
together. Does this mean all vermiculite has asbestos, not
necessarily but getting all the facts will mean you can make a better
informed choice.

Brigid Ryder

Vermiculite is often used by people working with PMC – it’s used to
support items in the kiln so the items don’t slump. Not all items
need support, but some do, say a bead, so you don’t get a flat spot.

When the PMC Guild folks stopped recommending alumina hydrate and
started recommending vermiculite, this very topic came up.

Tim McCreight researched it and the answer, as I recall, was that
yes, sometimes the two things – vermiculite and asbestos are
sometimes found in the same mine. But that vermiculite is safe to
use, and in fact, much safer than alumina hydrate, which is a very
fine powder.

He posted this answer on more than one PMC list (though I can’t find
it at the moment) and it was published in Studio PMC. Back issues
of Studio PMC can be found at, resources,

Elaine Luther
Metalsmith, Certified PMC Instructor
Hard to Find Tools for Metal Clay

Hello Orchidland,

Vermiculite is widely used in the plant nursery industry as a
potting soil amendment. I mean by the truckloads. They are not
exactly careful when making up a couple tons of potting soil!

I find it useful when firing a hollow form in PMC to prevent

Let’s use common sense and handle vermiculite with some caution to
avoid breathing the dust, as we should be cautious with any airborn
particles. My approach is to use moderation in all things, including
my approach to vermiculite - which I see no justification to
eliminate from my tool box.

Judy M. Willingham, R.S.
B.A.E. 147 Seaton Hall
Kansas State University
Manhatttan KS 66506
(785) 532-2936 FAX (785) 532-6944

Continue from:

Hi Gang,

There has been a little discussion about vermiculite and asbestos on
this thread and I just want to clarify: the most commonly used
soldering board here in Denmark and probably many other places in
Europe are made from vermiculite by a company named Skamol. They are
absolutely asbestos-free and a dream to work with. In the softer ones
you can stick in pins to hold your items-to-solder, and they do not
scratch your items. Stand up to at least 1300 degrees C. Only
drawback: they can be a little messy, as they leave traces of
vermiculite all over. You can see more about them on
(in English). They are exported world-wide, and should also be
obtainable in the US. Would like to hear if anybody can find them in
the US. Usual disclaimer goes here.

Kind regards from Bornholm, Denmark

Here is a place to get Skamol vermiculite board in the US:


The following comes from the EPA’s Information Page on Vermiculite.
Asbestos Contamination In Vermiculite

  Asbestos  contamination in vermiculite and vermiculite products
  has become a national  concern to a variety of federal agencies
  (EPA, OSHA, CPSC and ATSDR) and to many  private citizens
  throughout the country.  A tremendous amount of has
  been made available to the public via print, television/radio 
  and the Internet.  EPA's vermiculite pages provides users with
  basic  about Vermiculite and its uses, factsheets,
  Question and Answer documents, reports and links to EPA
  Regional vermiculite pages. Other relevant not
  included here, may be available from federal, state and local
  governments, industry, trade associations and international
  sources. Vermiculite and Its  Uses 

  What is  Vermiculite? 

  Vermiculite is the  mineralogical name given to hydrated
  laminar magnesium-aluminum-ironsilicate  which resembles mica
  in appearance. All vermiculite ores contain a range of  other
  minerals that were formed along with the vermiculite in the
  rock.  Vermiculite ores from some sources have been found to
  contain asbestos minerals  but asbestos is not intrinsic to
  vermiculite and only a few ore bodies have been  found to
  contain more than tiny trace  amounts. 

  Vermiculite mines are surface  operations where ore is
  separated from other minerals, and then screened or 
  classified into several basic particle sizes. Vermiculite is
  found in various  parts of the world. Locations of the
  predominant commercial mines are in  Australia, Brazil, China,
  Kenya, South Africa, USA and  Zimbabwe. 

  When subjected to heat,  vermiculite has the unusual property
  of exfoliating or expanding into worm-like  pieces (the name
  vermiculite is derived from the Latin 'vermiculare' - to breed
   worms). This characteristic of exfoliation, the basis for
  commercial use of the  mineral, is the result of the
  mechanical separation of the layers by the rapid  conversion
  of contained water to steam. The increase in bulk volume of 
  commercial grades is 8 to 12 times, but individual flakes may
  exfoliate as many  as 30 times. There is a color change during
  expansion that is dependent upon the  composition of the
  vermiculite and furnace temperature. 

  How Is Vermiculite Used? 

  Vermiculite has been used in  various industries for over 80
  years. It is used in the construction, agricultural,
  horticultural and industrial markets. Generic Applications -
  Loose Fill Carriers  Lightweight Aggregates Soil Conditioners
  Asbestos Substitutions Density Modifiers  Absorbents Fire
  Protection  Industrial Heat Insulation