Figure 6From: Nanoquartz in Late Permian C1 coal and the high incidence of female lung cancer in the Pearl River Origin area: a retrospective cohort study SAED pattern and DF images of quartz in C1 coal. (a) Typical SAED pattern (d = 1 μm) of the multiple quartz crystals in C1 coal; (b) DF image of quartz in parabolic or parallel fiber bundles; (c) and (d) DF images of quartz showing each fiber has a diameter of about 5 nm and is composed of crystallites 2*5 nm in size.Back to article page