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.
Some igneous rocks may display large crystals that are surrounded by a finer-grained material. Rocks with these two different crystal textures are called porphyry. It is thought that the larger crystals develop earlier in the rocks formation, while the magma is still deep within the earth.