Terralit, laterite

Has anyone heard of an expensive gravel additive called
Terralit? I was inquiring about laterite and this is what they 
suggested. The cost was about $35 Cdn for about a kilo. Is this
the "real thing"?

My wife's family lives in the Philippines. There should be plenty of
laterite clay there. If they send me some, how can we be sure it's
the real thing? Red volcanic clay from the tropics ok? It's easy 
enough to send a few ounces of the stuff by mail and possible to
ship kilos of the stuff provided we had the proper customs paper.