Agate is a common rock formation, consisting of chalcedony and quartz as its primary components. It is found in a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks. The Ancient Greeks loved to use colourful agates for ornamental purposes such as jewellry. Notably it was used to make the seal stones of Greek warriors. Interestingly agate bead necklaces have been found in the Indus valley dating as far back as the 3rd millennium BC. Sold as single stones