Are all proof coins struck more than once?
Harry779
Posts: 902 ✭✭
if all proof coins are struck more than once,does this show up under a microscope?
i have read that a second strike will never exactly line up with the first strike.you will probably not see it with the naked eye but it will be detectable...is that correct?
if medal press coins are pressed with more pressure than a business strike then how is that determined?
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<< <i>if all proof coins are struck more than once,does this show up under a microscope?
i have read that a second strike will never exactly line up with the first strike.you will probably not see it with the naked eye but it will be detectable...is that correct?
if medal press coins are pressed with more pressure than a business strike then how is that determined? >>
.....some info for you:
What's a proof coin?
A newly minted proof coin is also Un-circulated, however it is the way it is made that causes a difference in appearance and qualifies it as a "proof". To understand this, let's look at how coins are made. Coins are produced when two dies strike a blank piece of metal with tremendous force. One die is engraved with the front (obverse) design for the coin. The other die has the back (reverse) coin design on it.
A proof coin is made with
a specially polished and treated die!
By treating the die in a special way, the coins it produces have a different appearance. Modern technology allows the high points on the coin design to be acid treated (on the die). The background (field) design of the coin die is polished, resulting in a mirror-like look on the coin it strikes. This gives the finished coin a frosted look (frosting) on the raise parts of the design, with a mirror like finish on the background. This contrasting finish is often called "cameo". (See picture above.) On some older coins a cameo appearance is quite rare. The attribute "CAM", when added to a coin's description, means cameo appearance. "DCAM" means deep cameo, and indicates the cameo appearance is strong and easy to observe.
Proof coins are struck twice, or more!
Not only are proofs made using specially treated dies, each coin is struck two or more times by the coin die. By striking it more than once the metal is forced into all the crevices of the die, thereby giving a very fine detail to the image on the coin. This fine detail does not appear on some non-proof coins.
Grading proofs
Today's grading of proofs is similar to the grades used for uncirculated coins. The attribute "PR" or "PF" stands for "proof", and is used instead of the MS (mint state) to indicate a proof coin. Proofs (that are also un-circulated) will be graded PR 60 to PR70, with PR70 being rare or nonexistent in some cases. Because a proof coin can be mishandled or receive wear by cleaning or handling, proof grades can extend below PR 60. Example, a PR50 grade proof coin, is one that has had a touch of wear on the high points of the coin. Like uncirculated coins, proofs can experience toning, tarnish or darkening.
since proofs are always struck at least 2 times.....is this easily identified under a microscope?
and i am talking about a coin from the early 1900's
Additional proof steps have involved also polishing the coin blanks and even using a special annealing technique for them, such as passing them through the furnace on a belt rather than tumbling them in a drum.
Prior to about 1980, proof coins were struck once using a high pressure medal press. Before 1858 some "Master coins" or "Specimen" coins were struck more than once - details of operating procedures are inconclusive.
If the modern press is working correctly, you should not be able to see evidence of each strike. On older hydraulic presses (and screw presses) evidence of multiple strikes would be easy to locate.
Empty Nest Collection
"To commemorate this long-awaited event, the Denver Mint produced a limited number of specimen (or proof) strikings in 1906. An unknown number of proof 1906-D Liberty eagles, along with 12 proof 1906-D Liberty double eagles, were delivered for presentation purposes. For years, numismatists believed that these were the only two denominations to receive such attention in 1906. In 1976, however, Walter Breen examined a 1906-D Barber dime at the NCNA Convention in San Francisco's Jack Tar Hotel. He concluded that the coin was indeed a specimen striking due to the following characteristics: the dies are in their earliest state and have been brilliantly polished; and the coin was given at least two impressions from the dies as every device is as boldly defined as similarly dated proofs from the Philadelphia Mint."
Fascinating!
"Inspiration exists, but it has to find you working" Pablo Picasso
The branch mints did not have medal presses, and these were the only ones used to strike legitimate “proof” coins. It is reasonable to presume that a few special pieces were carefully struck at Denver in early 1906, but they would not be real “proofs.”
As for the comment that some dime was struck twice, that could happen anytime due to mechanical failure. Might also have been mechanical doubling.
Imitation proofs of cents or dimes could be struck on normal presses because the pressure could be adjusted high enough to bring up nearly all of the design. However, they would still nor match the mechanical results from a medal press.
Note: both silver and gold coinage alloys harden when struck. Multiple striking is only effective if the two blows are given in extremely rapid succession, or if the coin were heat softened between blows (as with the MCMVII $20).
"Keep your malarkey filter in good operating order" -Walter Breen
if the coin was pressed under extreme pressure,like a medal press....can this be determined by metal density or electron microscope or the thickness of the coin?
did medal press proofs/presentation pieces use a thicker planchet to begin with?
Modern multistrike presses operate at lower pressure than old hydraulic presses, and this helps lengthen die life. The additional detail from the second or third strike is evident only if you know what the coin is supposed to look like. Edge collars are designed to hold the coin in correct alignment so that doubled devices do not occur. (That type of mechanical control did not exist at the 19th century mint.)
The 19th and early 20th century situation is further complicated by the mints procedure of putting defective proofs (but still good coins) into circulation and counting them in th annual production total.
Of course once the coin is struck it does become denser (molecular lattice structure) and the thickness changes but it is imperceptible to the naked eye. One has to remember that the coin blanks (planchets) are annealed (softened) to allow the plastic deformation to readily occur. This procedure also allows the coin dies to repeat it's performance with little to no wear, but over time, the dies will eventually degrade and have to be refurbished or replaced, especially when it come to proof dies.
"Keep your malarkey filter in good operating order" -Walter Breen
recently a proof John Adams dollar was found with excess metal that was squeezed up and created a fin or a wire rim.
see here:
John Adams Proof Wire Rim
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no one seems to be able to tell me if a satin proof silver coin from around 1916 is black.(like a 2006 satin dime,or a similar appearance)
do these early satin silver coins (never mind that they are manufactured differently today) look "blackish"?
silver coin proofs (dimes and quarters)could possibly have been made in 1916 according to several different accounts of "big shots" receiving these coins.These coins are supposed to be satin coins.Would they be dark colored?
or would they be blast white?There have been "reports" of the satin 1916 proof quarters...where are they? has anyone actually SEEN one?
my coin is high relief,has a wire rim,pressed with new dies,blackish cromelike finish on the coin,extremly crisp details,wide rim almost all the way around except for a small spot near
6:00 (i have read about other proof coins with the same condition)and it just plain does not look like any other Mercury dime i have ever seen before.
If the wire rim was so common....how come i cant find one? I have searched for months and still have yet to find one single coin.
a proof silver would not be black unless toned badly
check out USpatterns and Heritage pics of these patterns to see if you have a pattern
I also am confused on multiple proof striking and medal presses
but defer to RWB for now as he does more research than I
its not like any of the pattern coins.I have seen them all.
When did they stop?
On occasion this artwork ended up on circulation strikes such as 1956-1964 and 1969D-1972D quarters. I believe these were made from rejected proof dies that were never polished nor produced proof coins. I have heard accounts, or rumours, that in later years some proof dies were recycled into production coins after sandblasting of the polished surfaces. Anybody have information on that? Or on this practice in earlier years?
With the end of silver coinage, or perhaps SMS. seems to be the cutoff. When proof coin production shifted to San Francisco, everything changed. I do not recall that anyone has done the research from1968 forward.
Harry779 - The main point is that collector's proofs were struck only at Philadelphia. They were more-or-less started as sets for sale beginning in 1858 and continuing through 1916 (cents and nickels only); then from 1936-1942; and 1950-1964. All were struck on a medal press and all were struck once.
There are all sorts of stories about special proofs from 1916 or 1917, and branch mint proofs and other things. Some are entirely phony (1917 proofs, for example), others might be simple confusion (1916 sandblast proof dimes confused with pattern dimes), others are nothing more than errors that have been copied for generations (certain 1916 patterns called “proof” when we now know they were struck normally). For every slightly unusual coin there seems to be an advocate for believing in imagination.
Re: specific questions.
no one seems to be able to tell me if a satin proof silver coin from around 1916 is black.(like a 2006 satin dime, or a similar appearance)…do these early satin silver coins (never mind that they are manufactured differently today) look "blackish"?
No. Freshly made satin proofs look like normal silver alloy, except they have a smooth, satin-like surface and almost no luster. Like any silver object they can tone various colors, or gray or black.
silver coin proofs (dimes and quarters)could possibly have been made in 1916 according to several different accounts of "big shots" receiving these coins. These coins are supposed to be satin coins. Would they be dark colored? or would they be blast white? There have been "reports" of the satin 1916 proof quarters...where are they? has anyone actually SEEN one?
No report of these has ever been independently substantiated. There is a 1916 Mercury dime in the Smithsonian that I think is a nice early strike and David Lange thinks might be a satin proof. From my examination, the coin lacks key features of a medal press piece and is not a proof.
my coin is high relief, has a wire rim, pressed with new dies, blackish crome-like finish on the coin, extremly crisp details, wide rim almost all the way around except for a small spot near
6:00 (i have read about other proof coins with the same condition) and it just plain does not look like any other Mercury dime i have ever seen before.
Your description seems closer to an early strike from new dies, than any sort of “proof.” The presence or absence of a fin (you call a “wire rim”) is not relevant, since it is not a required characteristic of a “proof.”
If the wire rim was so common....how come i cant find one? I have searched for months and still have yet to find one single coin.
The fin was complained about in late 1916 and early 1917 by vending machine owners. Most complaints seemed to be from the Chicago area. The fin made some of the dimes too thick to pass through the coin slots, and jammed the mechanisms. By nature, the fin is very thin and easily worn off. If you could go back to early 1917, you might find quite a few “fin rim” coins among the new dimes. The odds of finding one now are likely very small. The fin problem seems to have been fixed for CY 1917. (Complains did not appear to come from Denver.)
OK---my typing toe hurts…