Creating NHL Natural Hydraulic Lime from Hydrated Lime.

Hi,

I am looking to find a pozzolan to add to hydrated lime to create a hydraulic lime. Natural Hydrualic lime is available in the US but is shipped from Europe, negating the sourcing local philosophy. Does anyone know of a reasonably easy to source pozzolan? I have looked into fly ash, metakaolin etc but sourcing smaller quantities is hard and delivery costs are high.

I haven't tested this yet, but one recipe I saw called for "volcanic ash", which can be bought fairly easily. I think bentonite is one form of it.