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.
Rocks formed like this are called extrusive rocks, and they have small crystals, e.g. basalt, obsidian, pumice. Igneous rocks have interlocking mineral crystals. The crystals are arranged randomly throughout the rock. Igneous rocks are mostly non-porous.