On the southern shore of the Great Sand Sea, close to the Libyan border, we find one of the greatest mysteries of Egypt: the Silica Glass Field. The origin of this glass is a controversial issue for the scientific community: Some scientists argue that lightning strikes might be the cause, while others make the case that desert glass is the result of a meteor impact; still others insist that desert glass is of volcanic origin.

The Silica Glass Field covers an area that measures roughly 130 kilometers (80 miles) north and south by 50 kilometers (30 miles) east and west. The desert glass found in the Silica Glass Field is of extraordinary purity—approximately 98 % pure silica—and comes in various shapes (buttons, teardrops, dumb-bells, rods, spheres, or disks). Although commonly about 2–3 centimeters (1 inch) in diameter, they range up to a maximum diameter of almost 30 centimeters (12 inches) and weigh as much as 12 kilograms (28 pounds).