Niewmismatic Error Coins

Malaya & British Borneo QE II 1957H 50 Cents Coin With Over Size Wrong Stock Error.
Rarity: RRR
A “wrong stock” error is a coin struck on a planchet intended for another denomination.The result of using a blank intended for another denomination is called the Wrong Stock Error.
Struck on wrong planchet, sometimes classified as a Striking Error and sometimes classified as a Planchet Error, a coin struck on an incorrect planchet occurs when mismatched planchets are fed into a coin-stamping press. This results in a coin that has been stamped with a design intended for a differently sized coin. The resulting errors are prized by collectors, though they are usually caught during the manufacturing process and destroyed.

Read more: http://dniewcollectors.blogspot.com/2014/11/struck-on-wrong-stock-error-coin.html#ixzz3k7idhX4s
Shown here is a Malaya & British Borneo QE II 1957H 50 Cents(Normal Weight:9.34gm, Normal Diameter: 27.76mm ) struck on a Planchet weighs 9.46 grams and with a Diameter measured at 29.48mm.
Weight and Size (Diameter) are critical in distinguishing wrong stock errors.Wrong stock errors are best collected in their raw state. Many purported wrong stock errors that are encapsulated have no weight or measurement printed on the label.