* Basalt: Density typically ranges from 2.8 to 3.0 g/cm³.

* Rhyolite: Density typically ranges from 2.4 to 2.6 g/cm³.

Reasons for the Density Difference:

* Mineral Composition: Basalt is primarily composed of mafic minerals (rich in magnesium and iron) like pyroxene and olivine, which are denser than the felsic minerals (rich in silica and aluminum) found in rhyolite, such as quartz and feldspar.

* Chemical Composition: Basalt has a higher content of iron, magnesium, and calcium, which are heavier elements compared to the silica and aluminum found in rhyolite.

* Crystal Size: Basalt typically has smaller crystals than rhyolite, which can contribute to a slightly higher density.

In summary: The higher density of basalt is due to its mafic mineral composition, higher content of heavy elements, and generally smaller crystal size compared to rhyolite.