Has the Perth Mint Solved the Milk Spot Mystery?

Any serious coin collector knows that the nefarious milk spot will often sully the surface of your favorite coinage. Milk spots are white deposits that leave unappealing blotches on many silver coins and bullion bars.

Thankfully, collectors may soon have their frustrations ameliorated. A recent analysis by Australia’s Perth Mint has shed light on the issue.

Note the milky discoloration near the center of the coin

Suspicions of poor water quality and crucible contamination have been ruled out: metallurgists now believe that an accumulation of microscopic silver chloride debris are responsible for leaving the blotches. The analysis also indicates that the residue may have found its way onto the coins after their striking.

As a result of their recent discoveries, the Perth Mint will be implementing a couple of measures to lessen the appearance of the milk spots. The mint has scheduled routine cleanings of its compressed air line filters so as to remove any oil and water build-up. Meanwhile, the subsequent replacement of its air conditioning filters should eliminate the possibility of airborne microscopics finding their way into any manufacturing areas.

The Perth Mint

Although the analyses have not proven conclusive, the efforts by the Perth Mint have led to a considerable reduction in the amount of milk spots. At any rate, the measures enacted by the Perth Mint are sure to appease all of us anxiety-ridden collectors.

by Shaquille Brissett