Together with quartz, these minerals are classified as framework silicates.
One would say due to quartz' abundant nature, it is vital as it lays with feldspar in the continental crust. That is what makes both minerals framework silicates, it is also abundant in detrital sedimentary rocks due to its resistance to weathering.
Gold is an example of a native element mineral
Although Gold does not react much and rarely bonds with other elements, it is a very popular metal especially since it is found isolated.
For example, the incorporation of water molecules gives quartz, which is normally clear, a milky color.
Impurities found when molecules of minerals mix with different elements e.g., lithium, are what cause said impurities. An example used in the text is when water molecules are added to quartz changing is opaqueness to a milky white.
A paper page in a field notebook may also be used for the streak of some minerals. Minerals that are harder than the streak plate will not show streak but will scratch the porcelain.
There is a significance in streaking when it comes to minerals to better identify any impurities that could pop up. It also helps with look-alike metals disguising as another mineral.