Galemys,
Thanks for the clarification. One last question: How do they compare, assuming that the Fomes has been "processed," correctly, and they are both dry? Is one better than the other, and is it significantly better?
They both perform fantastic for a natural tinder, capable of taking a spark from flint and steel and smouldering for a long time. Both are on the top of my list together with cramp balls (
Daldinia concentrica, a blackish, hard fungus, according to internet these are found in the US as well but I haven't heard any American about them).
Chaga is scarcer and harder to find than horse hoof fungus, at least in England and here in the Netherlands, I don't know about North America though. As far as I know it only grows on birch. Birch trees can have a lot of blackish growth deformations that look like chaga on the outside but these are normally of a different colour on the inside and don't have the quality of taking a little spark and smouldering forever.
The burning qualities of both species depend on the specimen though, I never process my
Fomes fomentarius and some of them will work straight from the tree if dry enough, some won't.
Chaga:
http://images.google.nl/images?hl=nl&rls=GGLG,GGLG:2006-06,GGLG:nl&q=chaga&um=1&ie=UTF-8&sa=N&tab=wi
It looks burnt on the outside but it's the orangy/yellow inside that you need for tinder. The best parts feel a bit spongy/corky, the harder parts need a little more persuasion to get them to smoulder (scraping these harder parts to dust works quite well).
Chaga is also sold as a herbal cancer medicine (you can make it into a kind of tea).
Hope this helps, cheers,
Tom
PS
I haven't tried polishing with a chocolate bar but toothpaste and a piece of cloth works quite well, although it takes some time. Make sure to use a can that doesn't have aluminium coating though for this will not finish to a shiny polish. I have also succeeded in using a torch reflector as a parabolic burning mirror, so yes they work