A. Pius Alexandria Tetradrachm Head LEFT US $19.00 Sep-05-05 Seller amphoracoins Antoninus Pius, 138-161 AD, billon silver tetradrachm of 21.9 mm, 4.66. grams. Struck at the mint of Alexandria in Egypt. Obverse: Laureate bust A. Pius to LEFT. Reverse: Dikaiosyne standing left with scales and cornucopia. The light weight and corrosion on this coin are due to the fact that it was found in the sea. LEFT FACING BUSTS on these coins are extremely RARE.