Vermiculite is a flat-layered mineral akin to mica. It is heated to drive
off the water molecules that bind the layers, and when they're gone, the
stuff expands to the form we know.

If the stuff has no additives that are detrimental to plants, I cannot see
why it wouldn't be OK.

Personally, I don't like it in orchid media, as with time the water
molecules bid the layers again, causing the stuff to compact.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"DavidandAllision" wrote in message
...
I've been looking for a local source for coarse vermiculite. I came across
some
industrial grade coarse vermiculite used for packaging / mailing liquids.
It
Meets ICAA & IATA hazardous material requirements. Whatever that means.
What do
you think?