Chalcedony
Chalcedony is cloudy or translucent, white, yellowish-gray, blackish-brown, light to dark-blue, milky-white, and black.
This quartz is sometimes nearly transparent, waxy in lustre, and in some varieties has a light gray and transparent base with dark cloudy spots. This last variety is called “cloudy chalcedony”. Another kind, with gray and white stripes alternating, is known as chalcedonyx.
Iceland, the Faroe Islands, Hüttenberg, Loben, Saxony, Hungary, Nubia, Nova Scotia, Oberstein, Ceylon, India, Siberia, Carinthia, the Hebrides, the United States, and Canada are places where chalcedony is found.