3 New Glossary additions!
Thanks to discussions and threads involving 2Old, Onecent1909, Roller, Maineman750, and Mike Diamond, we have 3 new entries for our glossary! Thanks guys for all of your input!
PDS System: The PDS System is a highly structured cataloging system for mint varieties and errors. It was originally compiled by Alan Herbert in 1971. PDS stands for the three main divisions of the minting process: “planchet,” “die” and “striking.” Two more divisions cover collectible modifications after the strike, as well as non-collectible post-strike modifications such as altered, counterfeit and damaged coins. Thank you to forum member 2Old for writing this entry.
Roller Lines: These are very thin parallel striations, often seen on both the obverse and reverse going in the same direction. Though sometimes blamed on improper alloy mixture, these thinner, more even lines are more likely from dirty or damaged rollers from the rolling mill when it was reducing the planchet stock to the correct thickness for coin production. More commonly seen in the late 70s and early 80s. Please see this article by Mike Diamond for more information on striped coinage: http://www.coinworld.com/insights/di...nderstood.html Photo examples pending.
Partial Collar Strike: This occurs when a coin is struck which its edge only partially contained in the collar. The part of the edge which is contained in the collar is constricted from expansion as normal, but the portion not contained in the collar expands abnormally as a broad struck coin would. This creates a bi-level edge which resembles the wheel of a railroad car, and thus these are colloquially called “railroad rims.” This is somewhat of a misnomer, however, since the edge is really the part showing the effect, more so than the rim. Photo examples pending.
As always, I welcome constructive criticism if I have made an error or an ambiguity. Also, if you have good photo examples for Roller Lines or a Partial Collar Strike ("Railroad Rim"), please post them here or PM me, so I can add them to the entries. Thanks to everyone. Our resource continues to grow with everyone's input.