1970-D Jefferson Quarter Weighing 4.3g?

Very cool error! Looks to be more common that I realized, several 1970 D quarters on the bay.

ebay link https://www.ebay.com/sch/i.html?_nk...9a77847f7fe0

A split planchet on a clad coin would probably just be a cladding layer loss. This looks much more consistent with a 1970-D quarter struck on dime stock. An excellent find, and in very nice condition!

Not struck on a dime planchet but a quarter planchet that came from dime stock, big difference.

Smat, the metal for coins comes in sheets. For quarters and dimes, the clad layers are already in the metal sheets when the mint receives them. The sheets for dimes are considerably thinner than the sheets for quarters.

Someone at the Denver Mint in 1970 put a dime thickness roll of sheet metal into the cutting press for quarters. The resulting quarter planchets were the correct diameter, but were the thickness of a dime instead of a quarter. That makes them way underweight, and the planchets strike badly around the perimeter.

Thanks for breaking it down, Brand.