Review of clays and clay minerals in Jordan

Jordan is a country rich in clays of different origins. Clays of industrial importance are found in different stratigraphic units from Paleozoic to Cenozoic. The most potential clay minerals for industrial use are kaolinite, bentonite, and palygorskite. Other minerals as volkonskoite, illite/smectite, and smectite/kaolinite (black mud of the Dead Sea) are also common. The occurrence, nature, character, and economic importance of the different clay minerals in addition to problematic clays are given in this review. A recently novel geopolymerization process was developed to produce building materials (geopolymers) using Jordanian kaolinite. The products could be used as low-cost construction materials for green housing. They are characterized by high strength, high heat resistance, low production cost, low energy consumption, and low CO2 emissions. Volkonskoite areas (Cr-rich smectite) of Jordan can serve as natural analogues of a cementitious repository. Smectites are the most safety-critical components of the engineered barrier system for the disposal concepts developed for many types of radioactive waste (radwaste).