1987 D MD? RPM?......I'm sooo confused

[flyank]

When looking at this 1987 D mintmark, it appears to have what is a shelf like inner doubling of the D's vertical, but when I look at the RPM Book, many cents show this type of condition and are referred to as RPMs. So...as a beginner, this is quite confusing. What characteristics of this mintmark make it an RPM or MD....or something else? Education is a wonderful thing (right now I feel like I'm in nursery school!)...thanks for your help!

[willbrooks]

What you have there is called split-plate doubling. Very common on mint marks in this era.

Split Plate Doubling (Split Line Doubling): This occurs only on copper-plated zinc cents struck from mid 1982 to the present. During the striking of plated cents, the plating is stretched in order to form the raised design elements. Whenever relief is created from a flat surface, there must be expansion of the overall surface area, thereby putting stress on the plating. Sometimes, the plating will split on the rim-side of the devices, exposing the zinc core. The exposure will be in the same shape as the design elements, thereby creating a “doubling” effect. The exposed zinc is blue-ish in color.

edit: oh, sorry, I see you are referring to the small lip on the inside vertical bar. Looks like it cuts into the regular size of the D so I don't think it is an rpm. I would guess some damage to the punch itself or isolated machine doubling.

[jfines69]

Looks looks MD to me!!!