Vermicilite = perlite?

Hi Everyone,

I was planning to re-do my 10 gal tank this weekend with a vermicilite
mixed substrate.  I just found an old bag I had for houseplants which
I thought was vermicilite (sp?) but I know see that it is called Perlite.
It is Hyponex brand.  i'm assuming it's the same stuff, especially since
the bag says - a heat-expanded volcanic material that is sterilized to 
destroy harmful bacteria, pests, weeds and diseases.  Lightens and
loosens heavy clay soil for root aeration etc etc.

Could someone please tell me if this would be suitable for aquarium
use or not - I think it is.

Also, does everyone use glass tops on their tanks?  i'm thinking of foregoing
one on this 10 gal tank.