US Coins

Error coin progressions are surprisingly hard to verify

Error collectors are fond of assembling progressions — a series of coins struck by the same die pair that shows a pattern of change over time. In pursuing this worthy goal, collectors sometimes arrange their coins in an aesthetically satisfying but entirely incorrect sequence.

An accurate progression must be based on some aspect of a die or a coin that can only change in one direction. We start with a series of 1983-P Roosevelt dimes sent to me by error dealer Fred Weinberg. They were struck by an obverse die that had either split along the midline or that developed two radial, antipodal die cracks (see Collectors’ Clearinghouse, June 20). The obverse die was also covered by a die cap. (A die cap is a coin that sticks to a die and remains in place as a series of planchets is struck.) The split remains unchanged within the group of eight dimes. What does change is the clarity of the design. As the floor of the die cap became thinner, more of the design emerged. The progression is straightforward.

In a similar fashion, any series of coins sporting a brockage from the same source will show increasing distortion of the incuse image, with the most distorted images coming last in the progression.

Returning to Weinberg’s dimes, if one were to come across an example without any evidence of a die cap, there would be no way to tell if it was struck before or after the cap formed. That is, unless some other line of evidence would allow its temporal position to be established.

Had the split in this Roosevelt dime obverse die widened, that too would be a reliable guide as to which dime was struck first. In general, a pattern of brittle fracture proceeds in only one direction — toward greater severity. Die cracks grow longer, splits grow wider and cuds grow larger. A few exceptions occur, however. Coin metal that rises into a deeply recessed retained cud (retained die break) may make only light contact with the roof of that recess. The corresponding plateau on the coin will show only a faint trace of design. A slightly weaker strike, delivered earlier or later in the press run, could result in coin metal failing to contact the roof of the recess. The plateau would therefore be featureless and would be mistaken for a cud and a later stage in the breakdown of the die. It would also be indistinguishable from any genuine cud that would emerge later following loss of the retained cud.

Apart from capped die strikes and brockages, most other errors are tough to arrange in an indisputable progression. A group of broadstruck 2000-P Virginia quarter dollars shows variable development of a horizontal misalignment of the obverse (anvil) die and collar. (The coins were struck with an inverted die setup.) One would be tempted to arrange them in a pattern that shows a gradual worsening of the misalignment. A more imaginative collector might contemplate a gradual reduction of the misalignment. In fact, the true pattern is an erratic pattern of growth and diminution of the misalignment.

The true sequence is revealed by a steadily growing array of die gouges and accidental die scratches. The striking chamber was evidently full of debris, which created at least six different die stages defined by the swelling roster of imperfections. Had the die markers been identical among these coins, the actual sequence would have been impossible to ascertain. Interspersed among the six die stages are other coins that variously show, 1) a horizontal misalignment of the reverse (hammer) die, 2) an off-center strike or 3) a combination of 1 and 2.

While faint die markers, like fine die scratches and tiny die dents, can be lost to die wear, the typical signs of wear, such as radial flow lines and an orange peel texture, can themselves serve to distinguish late strikes from early strikes.

As with misalignments, any group of errors traceable to an unstable press component will be impossible to arrange in a progression without helpful die markers that increase in number or severity from coin to coin. For example, dynamic rotated die errors can travel in one direction or can reverse direction. Weak strikes can strengthen or weaken through a series, or show a fluctuating pattern of weakness.

Coin World’s Collectors’ Clearinghouse department does not accept coins or other items for examination without prior permission from News Editor William T. Gibbs. Materials sent to Clearinghouse without prior permission will be returned unexamined. Please address all Clearinghouse inquiries to or to 800- 673-8311, Ext. 172.

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