Clear quartz as a term is often used to describe some clear quartz that does have markings or milkiness within it. The reason for that is to distinguish it from other quartz derived crystals such as amethyst, rose quartz, citrine, aventurine etc.
Some refer to it as the master healer stone and It is one of the main tools used by crystal healers because of its balancing and cleansing / neutralising properties. It is good to hold or have around whenever you feel foggy, uncertain or would like to see your way more clearly. It is one of the most frequently used crystals by healers because of its wide-ranging benefits.
Clear Quartz Tumblestone (from Brazil) From £0.42