Agate (/ˈæɡ.ət/) is a common rock formation, consisting of chalcedony and quartz as its primary components, with a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks. The ornamental use of agate was common in Ancient Greece, in assorted jewelry and in the seal stones of Greek warriors, while bead necklaces with pierced and polished agate date back to the 3rd millennium BCE in the Indus Valley civilisation. This piece of Sliced Agate measures 3cm x 1.5cm x 1cm and is suspended on a fine 16 Inch 925 Silver Chain. Agate is one of the many Birthstones for the Month of June.