As far as I know it is as a form of volcanic pumice that has been crushed, they quarry it in Quebec I think, Its very permanent - I have found it promotes a very nice fine root structure. It is about 1/3 the price of Akadama for about the same amount per volume - I get akadama at
WWW.kimsnature.ca in Markhamm
Ill try to get some images of it in comparison to the two sizes of Akadama I have for the gallery.
Thanks for the warm welcome.
Edit: here is a pic of fine Akadama 12:00 - 4:00 Medium Akadam 4:00 - 8:00 and Eco Traction 8:00 - 12:00