The characteristics of quartz, feldspar, and mica.
Mica is usually reddish brown, because of impurities, the most obvious feature is flat, layered, single layer stripped off, thinner than paper, close to transparent, there is bright reflection, there is a hot electric iron.
Quartz according to the content of impurities from large to small, milky white, translucent and transparent, is the raw material for making glass, pure and transparent quartz stone is crystal stone, the chemical composition is silica.
Feldspar is milky, relatively crisp, irregular texture, is the raw material of porcelain.
Quartz: colorless, shiny, transparent crystal, generally white, colors are white streaks or nearly white; great hardness (knife not scratching); columnar and sharp end is transparent or translucent slightly like irregular shaped particles, is like glass or grease like light. Feldspar: a variety of colors, colorless, white, yellow, red, green, gray, black, etc., some transparent, some translucent. Feldspar itself should be colorless and transparent, colored or incompletely transparent because of the inclusion of other impurities. Columnar or blocky; fine-grained. Mica: flaky or scaly, color is black, brown, white, gray and so on; not highly conductive and refractory. Of the three minerals, feldspar is harder than mica; quartz is harder than feldspar; the hardest is quartz and the softest is mica.
