MAWE, John, English mineralogist, born in Derbyshire in 1764; died in London, 26 October, 1829. He opened a curiosity-shop in Piccadilly, and in 1804 went to South America on a business trip, but on his arrival at Montevideo was imprisoned as an English spy. He obtained his liberty soon afterward, but was sent to the interior of the country, where he remained several months. When the English under Beresford occupied Montevideo (in 1806), Mawe returned to the latter city and was attached to the staff of General Whitelocke, accompanying the latter in his unsuccessful expedition against Buenos Ayres. On his return to Montevideo he bought a schooner and sailed to Brazil, 11 September, 1807, making various explorations on his way. He was well received by the prince regent, who gave him permission to visit the diamond-mines of Minas Geraes, and also gave him access to the government archives, permitting him to take copies of charts and documents. Mawe returned to London in 1811 and became a well-known practical mineralogist there. He published "Travels in the Interior of Brazil, including a Voyage to the Rio de la Plata, and an Historical Essay upon the Revolutions in Buenos Ayres" (London, 1812); "Treatise on Diamonds and Precious Stones, and particularly those of South America" (1813 ; 2d ed., revised, 1823) ; and several less important works.