FIGURE 2.11 Quartz. Some minerals, such as quartz, occur in a variety of colors. These samples include crystal quartz(colorless), amethyst(purple quartz), citrine(yellow quartz), and smoky quartz(gray to black). (photo courtesy of E. J. Tarbuck)
FIGURE 2.11 Quartz. Some minerals, such as quartz, occur in a variety of colors. These samples include crystal quartz(colorless), amethyst(purple quartz), citrine(yellow quartz), and smoky quartz(gray to black). (photo courtesy of E. J. Tarbuck)