Like some opals is a term used to describe opals that have a MILKY or cloudy appearance. This type of opal is known as a 'MILKY opal' and is characterized by its opaque, white color. MILKY opals are usually found in the form of cabochons, which are polished stones with a domed top and flat bottom. They are often used in jewelry and can be found in a variety of colors, including blue, green, yellow, and pink.