Sintered Planchet Mint Error
Ads by eBay – Certified Mint Errors – Silver Dollars – Silver Half Dollars – Silver Eagles – Gold EaglesSintered planchets or plating is now known as improper annealing because it is thought that during the annealing process pure metal molecules, as in copper, migrate to the surface of the coin and form layers. Add to this some heat and oxygen and coins can become reddish, black, and spotted from oxidization of the purer metal.
Also See Improperly AnnealingModern improperly annealed planchets are worth $35 to $120 but early dates and denominations like an Eisenhower Dollar can be worth $400. Value depends on the grade of the coin as well and alloy.
Ads by eBay – Certified Mint Errors – Silver Dollars – Silver Half Dollars – Silver Eagles – Gold Eagles
Image courtesy of Heritage Auctions