Smoky topaz is the name for a type of gray, black or brown quartz, but it's not a type of topaz. Professional jewelers maintain that the smoky topaz gemstone doesn't exist. Quartz is a type of silicone dioxide, and amethyst and citrine are gemstones made of quartz.
Since quartz is one of the most common minerals found, it is inexpensive. Even beautiful smoky quartz doesn't cost as much as a smoky topaz would.
Topaz is a type of aluminum silicate. It can contain large amounts of water and fluorine. These determine the stone's properties, including its color, which can range among clear blue, pink and golden brown.