What is the difference between rhyolite and andesite?

Answer 1

They have different compositions. Most igneous rocks fall into a spectrum ranging from mafic (low silica, dominated by iron, magnesium, and calicum) to felsic (high silica, dominated by sodium and potassium)

On this scale rhyolite is felsic while andesite is intermediate. Rhyolite is dominated by the presence of quartz, potassium feldspar, and sodium-rich plagioclase. Rhyolite also tends to contain more volcanic glass. Common colors of rhyolite are light gray, white, and pink. Andesite often contains plagioclase with a fiar balance of sodium and potassium. Plagioclase is also a common dominant mineral. Andesite is darker than rhyolite, ranging from gray to almost black.

Answer 2

Rhyolite is a light-colored volcanic rock that is rich in silica and has a high viscosity, resulting in explosive eruptions. Andesite is a volcanic rock that is intermediate in color and silica content between rhyolite and basalt, and typically forms from the mixing of silica-rich and silica-poor magma.