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.
Answers. 1  Interestingly enough, while slowly cooled magmas have larger crystals, quickly cooled magmas have MORE crystals. I always thought that odd. So a piece of gabbro will have bigger crystals, but the basalt will have more. It has to do with the Gibb's Free Energy of Formation.