A coin can be common in certain grades and rare in others. A variety that is rare only in high grades, but that is plentiful in low grades, is a condition rarity. A famous example is the 1936-D Washington quarter dollar. In that year, at the three mints, the following quantities of quarter dollars were struck and are listed in the 2021 Guide Book at the values given for MS-65 grade:
1936 (41,300,000 minted) — MS-65: $90
1936-D (5,374,000 minted) — MS-65: $1,000
1936-S (3,828,000 minted) — MS-65: $235
Without further knowledge, someone investigating the investment potential of the quarters of this year might conclude that the 1936-S, with a mintage below that of 1936-D and priced for less than a third of the value of 1936-D, is a fantastic value, a sleeper, a situation just waiting to be discovered.
In actuality, in Mint State, the 1936-D is far rarer today than the 1936-S. The reason is that there was great excitement in the market, and the focus was on more than a dozen issues of commemorative coins that were released that year, plus older commemoratives already in collections. The series was hot, and the value of some of the commemoratives doubled or tripled within the year (and a few did even better than that).
Scarcely any attention was paid to currently issued Washington quarters, and most were paid out into circulation. A few years later, it was realized that hardly any mint-fresh 1936-D coins could be found. Bank-wrapped rolls (40 coins per roll) were plentiful enough for 1936 and 1936-S, as some still remained in vaults here and there. However, it seemed that nearly all 1936 quarters had slipped away unnoticed. It soon became a condition rarity — rare only if in Mint State, but common enough on worn grades.
The series of Morgan silver dollars (1878-1921) furnishes many examples of condition rarity. Some high-mintage issues, such as 1884-S, were paid out into circulation in the 19th century, with the result that well-worn pieces are plentiful today. However, relatively few were saved in Mint State, and true gem 1884-S dollars are both rare and expensive. In contrast, the 1884-CC, the lowest mintage issue of the year, exists today by the hundreds of thousands, as most were saved in Treasury vaults and survived to the present time. If you examine these mintages and values for selected grades in the Guide Book, you will see that a gem MS-65 1884-CC is relatively inexpensive, despite the variety’s having far and away the lowest mintage figure of the year. A VF-20 1884-S is common and inexpensive, but is a fantastic condition rarity in MS-65 grade and worth an impressive $225,000.