by Mark Milligan

A recurring question we receive at the Utah Geological Survey is: "Where can I get colloidal mineral supplements?" This article does not address where to purchase them, but what these products are and where they come from. "Colloidal mineral supplements" are cloudy liquids marketed as dietary supplements under many product names.

Suppliers claim they provide minerals not available from today's foods. To a believer in alternative medicine, these panaceas are touted to have the power to greatly improve your health by providing numerous essential minerals. To a skeptic, they are nothing more than snake oil sold to unwary fools.

As a geologist, not a doctor, I am unsuited to comment on positive, negative, or non-existent potential health effects. What I can address is the geology of the rocks used to produce these products in Utah.

Soaking specific types of pulverized shale in water allows some of the shale's organic matter to dissolve, creating a liquid that is termed a shale leachate. "Colloidal mineral supplements" are nothing more than shale leachates. Fine particles, which do not dissolve, are also suspended in these leachates.

At least some, if not all, of these elixirs are water-leached from carbonaceous shales mined from the Emery coalfield of Emery County in central Utah (more specifically the "G" bed / middle coal zone of the Ferron Sandstone Member of the Mancos Shale). The Ferron Sandstone was deposited approximately 90 million years ago durring the Late Cretaceous, near the close of the age of dinosaurs.

Index Map of Utah Coalfields. Within a coalfield, individual zones and beds vary in their ratio of carbonaceous material (altered plant material) to sediment (clay, silt, and sand). Carbonaceous shales are interbedded with purer coal, but contain much more inorganic silt than coal and are thus not useful as a fuel. However, the organic matter in these shales is essentially the same as the organic matter that composes purer coal.

The organic matter in the shales and coals originated as plant material that accumulated in wetlands and bogs. The organic matter began to change to peat when bacteria broke down the plant material. The peat was then buried by sediment and more plant material, which raised the temperature and pressure. As the peat compressed, water, carbon dioxide, and methane gas were forced out. With increasing heat and pressure the peat was converted to the types of organic matter found in coals and carbonaceous shales. After a great length of time, uplift and erosion exposed the coalfields so they can be mined at or near the surface.

At the surface, weathering further alters the carbonaceous shales before they are mined. After being mined, the carbonaceous shale is crushed and then soaked in water. After a period of time, perhaps 3 to 4 weeks, the water (leachate) is filtered off, bottled, and marketed as a "colloidal mineral supplement."

(Some of the information in this article was taken from the Society of Organic Petrology Newsletter, March 1997, Volume 14, Number 1.)