Silica is also richer in magmas formed by fractional crystallization If the magma is mafic-which is likely-silica crystallizes early and forms olivine at the surface (Figure 7). In certain cases (e.g.

As magma rises from 100 km (67 miles ... They crushed the samples, picked out and polished olivine crystals to find the fluid inclusions, and measured their CO2 densities using a Raman spectrometer.

As the magma cooled, heavier minerals such as olivine and pyroxene sank and formed the inner layers of the Moon, while the lighter mineral plagioclase floated and formed the outer crust of the Moon.