No. 40: Jul-Aug 1985
The mysterious Libyan Desert Glass (LDG) is almost pure silica. It occurs in pieces weighing up to 16 pounds in the Sand Sea of the Libyan desert, in an area roughly 130 by 53 kilometers. Most scientists have attributed it to meteorite impact.
The results of a thermal, microstructural, and chemical analysis of LDG suggest that it is more likely derived from a low-temperature chemical process rather than meteorite impact on sand.
(McPherson, D., et al; "Was Libyan Desert Glass (LDG) Formed by a Low Temperature Chemical Process?" Eos, 66:296, 1985.)
Comment. This short abstract in Eos is frustrating. What sort of natural chemical process could leave pieces of glass strewn over such a huge area? And what about the Darwin Glass in Australia?
Reference. Various natural glasses are discussed in ESM2 in the Catalog: Neglected Geological Anomalies. For more information on this book, visit: here.