USE OF COLOR IN MINERAL IDENTIFICATION

In some minerals color is directly related to a metallic element, is characteristic, and can be useful in identification. As examples,  azurite as shown in Figure 1A, is always blue due to the presence of copper, and rhodochrosite, shown in Figure 1B, is always pink to red due to the presence of manganese,. However minerals such as fluorite, colorless in it self, can be yellow, blue, purple, or green due to low concentrations of metal impurities.