What designates a "key date" in a series ?

Skipper53

I know "key date" refers to rarity but I've noticed many coin series have
several key dates.
I would have thought there would be one "key date". the rarest.
Is there a formula for deciding how many key dates there are ?


Skipper

clw54

There's no formula. It's not anything official, just words used to denote the scarcer coin(s) in a series.

mgoodm3

If it cost you a lot of money in crappy condition for it, it may be a key date. Not absolute, but pretty good.

WACoinGuy

Some series have different key dates depending on the condition you're looking for. The Peace Dollar series is a great example of this -- in lower grades, the 1928 is the key. But once you get past XF, the 1934-S takes over.

Skipper53

thanks WAcoinguy,
Something told me there wasn't an easy answer to this !

flaminio

Any coin that I don't own is a "key date" for me.

jdimmick

As mentioned "key dates" can change depending on the grade range in several series. A particular date may be the so called key in G VG, F, then drastically change as you get to higher grades, this can occur several times throughout the series as you climb in to the higher grades.

Also, the term "key date" and "rare" should not be considered the same in a majority of cases. There are many key dates that are quite expensive as compared to the rest of the series, but not rare in the slightest.

Some quick examples. 1909-s VDB expensive in lower circ grades and considered the key date by far compared to the other dates. But availble anywhere anytime and just about any quantity you would desire?

16-d Merc Dime same thing, lower circ grades are availble just about anywhere, but yet a key date an quite a bit more than any other date in the series in those grades.

several others