Magma's chemical composition
Lava is made up of crystals, volcanic glass, and bubbles (volcanic gases). When lava erupts it is made up of a slush of crystals, liquid, and bubbles. The liquid "freezes" to form volcanic glass. Chemically lava is made of the elements silicon, oxygen, aluminum, iron, magnesium, calcium, sodium, potassium, phosphorus, and titanium (plus other elements in very small concentrations.