Drum rock drilled from yellow dendrites Opal is something quite different, because he has a dull sheen and inclusions, which look like plants. The dendrites-Opal is a milky yellowish white to brownish cream-colored with black opal dendrites drawing. Generally, this mineral as a crude Opalart declared. The structure of each piece of jewelry unique. Often this is also known as dendrites Dendritenopal-called agate. To this mineral has two trading names.