Nanocrystalline silica from termite mounds.

To develop a better understanding of the physical properties and microstructures of the termite hill soils, we have carried out studies on the soil samples collected from two locations: near Dehradun, Uttarakhand and near Hauz Khas, New Delhi. Their elemental composition and microstructure were studied using different instrumentation techniques, such as powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope (TEM) and energy-dispersive analysis of X-ray (EDAX). α-Quartz (SiO2) was present in both the samples, while the sample collected from Hauz Khas, Delhi also contained β-cristobalite phase of SiO2. TEM–EDAX showed that termite hill soil consisted of silica (quartz), aluminium oxide, manganese oxide and iron oxide along with small percentage of potassium and calcium. Our studies highlight the potential to generate α-quartz from all termite hills. It is also possible to obtain the less common β-cristobalite form of silica in certain termite mounds. [ABSTRACT FROM AUTHOR]