Final answer:
Magmas with high silica content (> 65%) are related to ultramafic rocks like peridotite, composed of minerals such as olivine and pyroxene. Peridotite forms from the mantle, with ore minerals like magnetite appearing in lesser quantities. In glass production, silica along with other oxides forms the primary constituents accounting for the mass of manufactured glass.
Step-by-step explanation:
The magmas with the highest percentages (> 65%) of silica content are often associated with the formation of rocks such as peridotite, which is considered an ultramafic rock due to its high content of magnesium and iron. Peridotite chiefly comprises minerals like olivine, pyroxene, and sometimes contains ore minerals such as magnetite, ilmenite, and chromite. This rock originates from the Earth's mantle, which is known to be extremely hot, resulting in the outward flow of heat and certain physical properties that are indicative of the high temperatures present beneath the Earth's crust.
In the context of manufacturing glass, components such as sodium oxide (Na2O), lime (CaO), magnesia (MgO), and alumina (Al2O3) are combined to create a mixture that comprises around 70 to 74% silica by weight, which accounts for over 75% of the manufactured glass. These components help define the basic chemical structure and properties of common glass products.