You pay an entrance fee and keep what you find. Some mines are by appointment only. There are many types of quartz, such as bubble quartz, smoky, phantom etc. This page is an overview of the varieties you can find, with photos and text on additional pages. Coontail Quartz Not the strict crystallography term, but habits and growth patterns exhibited by quartz, such as twins, burs, tabulars, faddens, etc.
Inclusions are other minerals found inside quartz crystals.
Some are lovely, others have mud in them, you can find many things captured by quartz. A geological explanation of occurences of quartz in the state of Arkansas. Although quartz has a unique structure, so do many other minerals. That in combination with the chemistry is what makes a mineral a mineral. Crystals have a huge following of metaphysical advocates.