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.
Intrusive Rocks. Igneous rocks which form by the crystallization of magma at a depth within the Earth are called intrusive rocks. Intrusive rocks are characterized by large crystal sizes, i.e., their visual appearance shows individual crystals interlocked together to form the rock mass.gneous rocks which form by the crystallization of magma at the surface of the Earth are called extrusive rocks.