Cat C+E Licence. As category C but with a trailer over 750 kg. Driving this licence will be in either a full articulated vehicle or a draw bar (wagon & drag). This is the largest vehicle you can drive in the HGV industry.
The desert glass is nestled between 100-meter tall sand dunes in a very remote part of southern Egypt. After the 1932 discovery there were only two other expeditions (both in the 1930s) to the region until 1971, when three scientists spent two hours collecting only twenty-four samples.
The most reasonable scientific explanation is that Libyan desert glass is a type of tektite, a kind of natural glass with very high silica content. Volcanic glasses, which are fairly common, generally contain 50 to 70% silica content. Tektites, which are much rarer, contain much higher amounts of silica.