Final answer:
Turquoise (blue), malachite (green), and azurite (blue) derive their color from copper-based compounds. Transition metals, particularly copper, are responsible for the vibrant hues of these minerals.
Step-by-step explanation:
Turquoise (blue), malachite (green), and azurite (blue) all get their color from copper-based compounds. These minerals are known for their vibrant colors, which are a result of the presence of transition metals in their chemical structure, particularly copper. In the case of turquoise and azurite, the blue color is due to copper(II) ions, while for malachite, the green color also arises from copper(II) ions but with a different anionic group.
The mineral azurite contains the compound Cu3(CO3)2(OH)2 and malachite has a similar composition of Cu2CO3(OH)2. Both of these minerals sometimes occur together, forming striking specimens. On the other hand, turquoise, a phosphate mineral with the chemical formula CuAl6(PO4)4(OH)8ยท4H2O, owes its color to copper as well. These minerals provide important pigments that have been used historically in artwork and decoration.