That is, if you observe the spectrum of a star and can determine the wavelength where the emission peaks (Î»max), you can calculate that starâs temperature. Here is another copy of the plot that we studied in Lesson 3: Figure 4.1: Two-dimensional plot of the spectrum of a blackbody with different temperatures.
Igneous rocks usually contain the most crystals. The longer it takes the magma to cool, the larger the crystals.
Biotite is the most abundant mica in the quartz-rich regions and exhibits a weak planar foliation. Quartz and feldspar crystals are up to 0.5 mm in size. The mica-rich lithology is dominated by muscovite, with minor (<20 vol%) biotite, quartz and plagioclase. Mica grains are upto 2 mm in length and exhibit a well developed planar foliation. Garnet porphyroblasts are present in both lithologies.