GTG, improperly annealed (sintered) quarter?

derryb

Better than normal strike?

Alongside a normal quarter:

ifthevamzarockin

Discolored after roller damage. Details grade=roller damage

ricko

Coins are not sintered... that is a metallurgical process the mint does not employ.
Sintering is the process of compacting and forming a solid mass of material by heat or pressure without melting it to the point of liquefaction.
Cheers, RickO

derryb

Improperly annealed coins are often incorrectly referred to as "sintered" by collectors. Thus the use of the word in the thread title for those not as smart as RickO.

BAJJERFAN

I have a state quarter that looks like that. It looks like someone coated both sides with charcoal. Someone some time back referred to it as struck on a sintered planchet.
IIRC nickel planchets are too hard as is and must be softened before striking.

derryb

@ifthevamzarockin said:
Discolored after roller damage. Details grade=roller damage

I believe that because the discoloration is present at the rolling machine damage on the obverse, you are assuming the coin's surface was discolored after going through the rolling machine. Would not the discoloration from being improperly annealed be much deeper than just a surface discoloration? This could explain the discoloration below the surface where rolling machine damage is present on the obverse.

ifthevamzarockin

I understand what you are saying. If the metal is the same color all the way through it would not scratch a different color. The chance of that is very remote. It is kind of funny you ask about this just as I am going through many rolls of quarters. I have found quite a few very dark and off colored quarters in the last week or so. All have been some type of post mint discoloration with a fair chance of being caused by heat.

RogerB

Neither coins nor planchets are "sintered."

Discoloration can have many sources.

ifthevamzarockin

Your coin clearly has some contact marks and the wheel damage so it is not an uncirculated example. One more little scratch with a pin or staple would not affect the grade of an already damaged coin and might show you the silver/nickel color below the dark discoloration.

derryb

Unusually good strike? Note Washington's hair details. I find this unusual for a pre-statehood quarter.

And yes, many of us are currently searching rolls of quarters. LOL

ifthevamzarockin

Here is a random one I just took photos of for strike comparison and looks to be in about the same grade.

derryb

further research revealed a diagnostic from Fred W. Basically, "if the reeded edge is also discolored then it is not an improperly annealed planchet." Something to do with the striking process on an annealed planchet will result in a normal looking edge.

My edge is discolored, so not an annealed planchet. So much for "hot' off the press. And now, back to those boxes of quarters. Seven boxes and no 2019 quarters. I'm assuming this early in the year a box with new coins will be a box of only new coins.

BAJJERFAN

This is the one I have.