The first one ounce Silver Koala was issued in 2007 by the Perth Mint, all Silver Koala's have a $1 face value to them, These coins are considered legal tender but their intrinsic value will exceed that of their face value. The Koala bullion coins have a silver purity of .999, with each coin weighing 31.135 grams or one ounce. The coin generaly features a Koala on the reverse of the coin which is changed each year with a new design, and a image of Queen Elizabeth II on the obverse.