It seems to be related to both silica and aluminum... plus I know volcanic materials almost always have some level of residual mercury. I see a lot of good marketing, but where are the independent studies to conclusively prove that zeolite is free of any residuals. It is used in industry for purification and may indeed be helpful to bind and eliminate mercury, but there are too many good questions that I would like to see more research from independent sources before I would try or recommend it to anyone else.
