Fig. 7From: Characteristics and origin of a new type of polyhalite potassium ore in the Lower Triassic Jialingjiang Formation, Puguang area, northeastern Sichuan Basin, SW ChinaMicroscopic photograph of the polyhalite crystals under cross-polarized light (XPL). a A short-cylindrical polyhalite crystal from the Well ZK001, at 3085 m depth; b A long-columnar polyhalite crystal from the Well HC3, at 3444 m depth. H = Halite; Pol = PolyhaliteBack to article page