graphite, hematite, talc, sulfur, gypsumgalena, muscovite mica, halite, biotite micamagnetite, calcite, dolomite, flurite, pyroxenepyrite, amphiboles, potassium feldspar, plagioclase feldspar, olivine, quartz, garnet
Feldspar is used in the glass industry, so it would be needed to make the windows. It's also used to make bathroom tiles. The principal use of ground mica is in gypsum wallboard joint compound. Ground talc is used in producing roofing materials and in paint.
Poor product quality and fit.