Hastings' Dictionary of the Bible (1898)
PITCH. This word is used in the Bible for asphalt or bitumen, a light, inflammable, and nearly black mineral which in its soft form is called slime. Gen 14:10. In this latter state it was formerly obtained in pits near the Dead Sea (hence called the "Lake of Asphaltites"). On exposure this pitch becomes dry and hard like mortar, for which it was often used, especially in stone-work. It was also employed for coating the outside of vessels and for making watertight the papyrus boats of Egypt. Gen 11:3; Zech 6:14; Ex 2:3. There is reference to its inflammable nature in Isa 34:9.
The ancients obtained pitch in various localities of the Old World. At the present time fragments of asphalt occasionally rise from the bottom of the Dead Sea, having been dislodged by earthquakes and other causes, and are washed ashore.