Though the color of agate varies depending on the type, this popular stone long remarked for its beauty can be identified by its signature bands and translucent luster. Agate forms as a result of igneous rock marrying with the silica deposits in groundwater. The colorful bands that give the semi-precious stone its trademark bands are layers of agate deposits that develop on top of each other. Agates are banded types of chalcedony that come in a range of colors including pink, red, brown, white, purple, black, gray and yellow. This palette array comes from the impurities within the groundwater’s composition. As agate stone belongs to the quartz family, it has a trigonal crystal system and a durability Mohs score of 7. This cryptocrystalline mineral is made up of silicon dioxide, a plentiful composition explaining why agates can be found so commonly around the world in places like Brazil, Egypt, Nepal, Germany, India, Italy, Mexico and the USA.