Aquamarine is the blue variety of the mineral Beryl, and is classed as a semiprecious stone. It is a favourite in jewellery, and lower quality Aquamarine can be found fairly inexpensively in tumbled and raw form. It is also the birthstone for the month of March. The largest Aquamarine ever found was discovered in Brazil in 1910 and it weighed 110kg. In the Middle Ages, Aquamarine was prized as the most superior material for fortune telling crystal balls; whilst in 1377 William Langland praised the gemstone as an antidote for poison.