Mt. Vesuvius has dacitic to rhyolitic lava. Dacitic lava's silica contents are lower than those of rhyolitic lavas. Both dacitic and rhyolitic lavas are viscous and both can cause great destruction.
Dacitic lava is gray or black in color. It contains minerals such as pyroxene, amphibole, feldspar and 63-68 percent silica. The eruption temperature for dacitic lava is 1,500 to 1,800 degrees Fahrenheit. Dacitic to rhyolitic lava is so dangerous because it contains a high amount of crystals.
Mt. Vesuvius erupts according to the Plinian model of eruption. This involves a column of ash as tall as 28 miles being pushed up from the volcano into the stratosphere. An umbrella-shaped cloud of ash forms at the top of the column. The Plinian column can collapse and create fast and destructive volcanic mudflows. These eruptions are also described as explosive, as the volcano produces a mix of gas and solid particles, which cover the territory around the mountain.
Mt. Vesuvius' most famous eruption occurred in 79 A.D, when two Roman towns of Pompeii and Herculaneum, near Naples, were destroyed together with all their inhabitants. Buildings were buried under the layers of mudflows, ash, pumice and volcanic rocks, and became time capsules for historians to study the everyday life in the Roman Empire.