Black Agate Celestial Sun Clock Gold Printed Altar Tile w/ Crystal Quartz. Minor imperfection is normal as it is natural stone. Size & Shape are approximate. The Black Agate Celestial Moon Phase Sun Clock Gold Printed Altar Tile w/ Crystal Quartz is a unique and beautiful piece of decor that is perfect for any altar or sacred space. This stunning tile measures 3 inches in diameter and features a black agate stone that has been expertly polished to bring out its natural beauty.