are there different types of quartz?
['Amethyst. Amethyst, the purple variety, is the most popular and valuable Quartz gemstone. ... ', 'Citrine. Citrine is the yellow, orange, or reddish-brown variety of Quartz. ... ', 'Smoky Quartz. ... ', 'Rose Quartz. ... ', 'Rock Crystal. ... ', 'Milky Quartz. ... ', 'Rutilated Quartz. ... ', 'Ametrine.']