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.
up with each other and the crystals have more time to grow large. For this reason course-grained rocks, such a pegmatite (which is a textural term meaning having crystals larger that 1 inch [2.5 cm]) are more likely to have large mineral grains/crystals that potentially could yield gems of sufficient size for cutting.