Condition
The condition of the coin will greatly affect its price. If it is in "BU" condition (Brilliant Unused) it will be at its most valuable. If it has been used and has suffered from wear and tear its value will drop accordingly.
Gold content and size
Gold marks minted at this time measured 23mm in diameter. The gold content is .2304 troy ounces (a troy ounce is a weight measurement used specifically for gold and equals 31.1 grams). Its "fineness", a measure of the gold purity, is 0.9, which makes it about 21.5 karats.
Value
The value of a gold mark will vary according to its condition. In 2010 gold marks listed at auction houses at prices ranging from $334 for a slightly used specimen to $545 for an almost unused one.