The document discusses minerals that form from igneous magma, called pyrogenetic minerals. It states that since oxygen and silicon are most abundant in magma, silicates like olivine, enstatite, and orthoclase are the main igneous minerals. Pyrogenetic silicates fall into three categories: orthosilicates, metasilicates, and polysilicates. Sodium, potassium, calcium, magnesium, and iron form different silicate minerals depending on the amounts of silicon and oxygen available. Minerals also vary between those with low and high silicon content based on the magma composition. Common igneous rock forming minerals include quartz, feldspars