Kind of Marble is a term used to describe a variety of stones that are commonly used in jewelry and other decorative items. AGATE (5 letters) is a type of quartz that is characterized by its banded layers of different colors. ONYX (4 letters) is a type of chalcedony that is usually black or white with bands of color. TAW (3 letters) is a type of marble that is made from calcium carbonate and is usually white or light gray in color.