Halloysite market size worth $50Mil by 2025!!!, page-84

Worthwhile noting that in his intro he says:

While synthetic nanotubes have been the subject of much attention, they have proven expensive to manufacture. The idea of a natural nanotube has great appeal to the scientific community but also to industry. It would seem clear that a nanotube, with a price similar to kaolin, would be a hit.

So sounds like in his opinion there could be alot of interest, however its price dependent. Not trying to get into a pricing discussion, more that sometimes its important to read everything, and not just the conclusion