Hi guys, Just purchased an upgrade for a German coin. Everything points to it being real, close Weights and diameters. I’ve asked on some German forums and they agree it looks genuine. The Specific gravity test is good, not magnetic but slow down the magnetic slide. I am concerned with the ping on both coins not being identical. I was told they were struck by men not machine but not sure how much this can account for changing the pitch ? My original has the long high pitched noise and the other is more dull and shorter duration. Any help would be greatly appreciated! Regards, Mark
P.S. I cannot upload a video of the ping but these are the coins. 1817 is my current and 1818 is the upgrade. Sent from my iPhone using Tapatalk
Striking pressure can result in slight differences in the ring as can whether or not it is struck with or without a collar. For struck without a collar the diameter and thickness will also vary which can also affect the ring. Slight differences in alloy can have an effect as can tiny internal cracks and voids in the metal. Ring can be a clue, but it is not reliable for counterfeit detection. (Sometimes a internal flaw in the metal can result in the coin not ringing at all. This is known as a "dumb planchet".)
Thanks, I was beginning to get worried. The coins are not perfectly round, the diameter of the 1817 at the smallest is: 32.28mm and largest 32.82mm. It has a thickness of 1.26mm. weighs 12.91g the density of this coin comes in at 10.41 1818: Largest diameter is 33.08mm and smallest 32.69mm weighs the same at 12.91g Thickness the same 1.26mm The density of this coin comes in at 10.66 NGC Quotes 13.08g for this coin. Of course there can be margin for error given the time of the striking.
Exactly what I was thinking, as well. The 1817 appears to have planchet inclusions visible left of the coat of arms. There are probably other interior inclusions like these that will affect the ring of the coin. I would imagine that if you were to take one such coin like this and chill with liquid nitrogen, then immerse in boiling water, it would pop like an ice cube and give you a "valuable error coin."
I think the inclusions are die cracks. The 1817 is not really the coin I’m overly concerned by. The 1818’s ring and additional diameter has me thrown. I can’t find a hard line on diameter but if the later issues are anything to go by it should be 32.5mm. Then again as I look at both one is off centre strike and the 1818 is full. Maybe this could be the reason for the larger diameter. The edge of this coin is nicely struck, the 1817 appears to be weaker and/ or worn in comparison. I have the 1820 & 1821 types of these coins already. Unfortunately they’re in NGC Holders and I have not yet arrived at a decision to break them out yet although I won’t rule that out ! Sent from my iPhone using Tapatalk
Until the mid 1820's all US coins were struck in what is called an "open" collar which was used to relatively center the planchet between the dies but did NOT restrain the expansion of the coin during striking. For that reason the final diameter of the coins all varied slightly depending on the force of the strike and the annealing of the planchet. A soft strike or improperly annealed planchet would result in a smaller diameter, a strong strike or soft well annealed planchet would result in a larger diameter. I find large cents can vary by up to as much as 2 mm in diameter. Starting in the mid 1820's they started experimenting with close collars that strained the expansion resulting in consistent diameters. After 1836 all coins were struck in close collars.
