Understanding counterfeit detection
fruitloops
Posts: 343
This will be a thread periodically updated as I get more material to put in this thread, it is a work in progress.
Overview of counterfeit detection:
Counterfeit coins are becoming more of a problem as time passes. It is all too apparant, and grading company slabs are even being targeted. Fakes can range from crude (cast copy), to excellent (transfer die struck). Many gold coins coming from the middle east are exceptional, and it is a rule to remember that some of the best counterfeits, if it looks too good to be true, it probably is.
In the summer of 2002, first brought to the attention in the magazine Coin World, a very strange error coin came. The existence of a 'mule' consisting of the obverse of a 1959-D cent and the reverse (wheat ears) of a cent from 1958 (or earlier). To Bob Campbell, a famous autheticator, the coin just didn't "look right", he said "Something about the coin just didn't seem right", later he said, "The fabric was there and everything pretty much looked correct, but it just felt wrong -- not a physical kind of 'feel' but more of a gut like feeling." Indeed, the coin looked too good. How could such a spectator error go unnoticed ? That's because the coin was a forgery, different from a counterfeit. Generally counterfeit coins are contempoary, they are mean't to be used in circulation. Where as a forgery, is made to fool numismatic experts and dealers.
More about the coin, it was actually made by infamous Mark Hofmann. He once said, "If I can produce something so correctly, so perfect that the experts declare it to be geniune, then for all practical purposes it is geniune. There is no fraud involved when I sell it."
In his book Numismatic Forgery, Charles M. Larson, who was the sergent at night when he worked at the prison which Mark Hofmann was sentenced to, talked and interviewed Hofmann several times. Hoffman told Charles that he used an ingenious method of creating dies using an electroplating process.
You can read more about Numismatic Forgery in Charles Book, Numismatic Forgery
A few rules of thumb:
Generally there are different types of creating counterfeit coins and how to spot them. Many times counterfeiters would actually melt down a very worn (but authentic) $20 double eagle to make several $1 gold coins, which have a high numismatic value relative to their intrinsic, or gold content. This way the gold used has the same fineness as geniune mint gold, as well as the proper alloy. (Because the worn $20 is a geniune coin, it can be purchased for less than fifty dollars over spot of the gold it contains.)
As a general rule, it is said that coins that are EF or lower, chances are it is geniune.
Overview of different counterfeit types:
Cast counterfeits:
Generally, cast counterfeits are the most poorly made. Often you will see blobs of metal through the letters or devices of the coin. Often times, as well they can be identified by a seam that runs about the outside edge of the coin. Casting can be made from plastic molds, using centrifugal force. Cast counterfeits, unlike transfer die high quality counterfeits, are often underweight and may use a different material (such as tin), instead of silver if the coin is a silver coin.
Electrotypes:
These are generally used by museums.They are made by impressing a geniune coin nito a soft substance and electroplating the negative impression, creating a positive shell. Generally the edge can give this away, as with cast counterfeits many electrotypes have a seam around the edge. Generally when "rung" electrotypes will not sound right, because of the process made.
Transfer dies:
These are the most common used and also the most deceptive.
The counterfeiters actually create a working die this time, but since they are using the same die all imperfections struck from those dies will go onto the coins. Sometimes there will be a blemish on the die, and the counterfeiter tries to remove it.
A typical struck counterfeit:
This leaves short, stubby lines on the finished coin called toolmarks. Alot of Indian head gold coins have toolmarks in the recess of the neck. Also since the counterfeiter is using the same die, there are things known as repeating depressions. The reason they are repeating is because any coin struck with that die will have the same imperfection. A geniune coin must be sacrificed as a host to make the transfer dies. Because the geniune coin used will have contact marks, the metal flows into the planchet creating what is known as depressions on the counterfeit coin.
High quality (probably middle eastern) struck counterfeits, all returned body bagged as counterfeit by PCGS.
These are small, often circular crators in the coin which often blend with the surrounding field, but because they were struck, they have luster inside them. Often a contact mark is shiny and does not blend in with the fields of the coin because the metal is disrupted.
It is said that the most common counterfeited coins are the ones collectors buy the most, because of demand. This is what Charles said in his book, Numismatic Forgery. For some reason, there are few counterfeit coins before 1840.
A counterfeit gold coin (probably another base metal) in a counterfeit PCGS slab. This was found on ebay from a seller oversea's.
Counterfeiting slabs are becoming more of a problem and NGC has taken actions with this in their slabs. PCGS has also taken action, issuing a warning to be careful of counterfeit PCGS slabs, and how to spot them.
Spark Erosion Counterfeits:
These are generally easy to detect because how they are made.
In this process, A geniune coin is put in an electrolyic bath where the coin faces the counterfeiter's die steel. An electrical current spark is charged t hrough the coin so that the spark goes across the shortest gap between the coin and die, creating the coin's design onto the steel die
Often times these coins are heavily pitted because of this process..so the counterfeiter's polish the dies to make up for this. These can be detected by their lumpy devices, and are often found on small type coins like cents and dimes.
Some rules of thumb:
Because of the transfer die process, many gold coins use this. Also, because a geniune host coin is used and a crude die is made, called an impact die, there is generally loss of detail on the counterfeit coin.
A good thing to do is look at many geniune coins in a paticular series. Once you know what a geniune coin looks like, in general, counterfeits become much easier. Generally geniune coins have sharp, crisp letters and devices, numbers as well. Weak fatty letters and devices are a dead giveaway the coin is counterfeit. Please remember that generally you need many different attirbutes to determine a coin throughoutly counterfeit, for example if you just find a depression or two on the coin, this is not enough to deem it counterfeit. Depressions can also be mint made, but often they do not have the luster that a counterfeit coin has.
Another thing to look for on counterfeit gold coins are spikes from the denticals or devices, such as stars of the coin. I'm actually not sure what spikes are caused from, but I know that spikes along from the denticals ont he coin are not enough to deem it counterfeit; as discussed earlier because sometimes geniune coins have them too. According to expert numismatic authentication expert Randy Campbell, about 3% of geniune coins have them.
Color is another thing to look for on counterfeit coins. Generally sometimes, the color is just "off" and it doesn't look right. This can only come with years of looking at geniune coins and knowing your series well. For example, branch mint coins struck in Charlotte, North Carolina usually have a red hue, where coins minted in Dahlonega, Georgia, or new orleands, and also Louisiana often have a greener cooler. Note: I have read in an issue of Numismatic News that coins from the southern mints, such as Dahlonega and new Orleans, the coins often have a lighter color, and this is because these coins have a higher silver content in them, mixed with the gold alloy produces a different color. This seems to contrast with what I posted earlier...but I believe it is the correct one.
On cast counterfeits, often the coin is not the correct weight weight, so you may need to weigh them. Many transfer die struck gold coins are the proper weight and fineness (because of , in some cases, a melted double eagle makes several gold dollars)
Many counterfeiters do not take the time, unlike the mint, to polish their dies. Therefore lots of die polish relevent in protected area's of the coin, are a good sign or a possible sign it is geniune
Often times what counterfeiters will do is buy a blank planchet, which the mint has made (on accident) (such as a silver dime planchet for a 16-D mercury) and use that to create the counterfeit coin.
I hope this information helps learning more about counterfeits.
The key is to look at as many coins certified by the Top TPG's, that are geniune, so you know anything that doesn't look geniune is suspect.
Credit goes to Numismatic Forgery, United States Gold counterfeit detection guide by Bill fivaz, and the guide to grading and counterfeit detection by PCGS.
Counterfeit dies made from chinese counterfeiters:
Excerpt from Bill Fivaz book, on counterfeit gold. Notice the linear depressions (which is from when something gets stuck on the die and is struck, leaving a depression), and the luster within the other depressions:
(Note: The following are notes taken from my ANA counterfeit detection seminiar I took at the ANA Phoenix show with teacher Brian Silliman. They are filled with many tips and tricks, I hope you enjoy them)
Notes from authentication, grading, and conservation class taken at the ANA national money show pre-convention seminiar in march, in phoenix.
Authentication:
Contempoary counterfeits are circulated
Q: What are altered coins?
~ Date alteration:
A: One or more of the digits are "altered" so the coin can be passed as a more valueable date.
TIP! --> *First coins made by counterfeit dies look too prooflike (PL), unreal. Worn down counterfeit coins made by counterfeit does look more deceiving.(Worn out dies)
TIP! --> Bay Area counterfeits -- (Look up)
~Mint mark alteration:
* The addition or removal of a mintmark to produce a more valueable specimen.
Alterations:
Form of a counterfeit coin. Note: This is not the same as surface alteration on a coin.
Depressions. --> Depressions are contact marks on an orgininal coin used as a host (sacrificed) on a counterfeit die to make counterfeit coins.
Interesting note -->
Struck counterfeits are most often seen on gold coins.
Alterations are most commonly seen on all key dates or mintmarks and on most better dates.
TIP!--> Take the How To Detect Counterfeit and Altered US coins ANA correspondence course.
TIP! --> Most struck counterfeits are uncirculated.
Recommend references for further reading:[list][*]ANA Reprints from the numismatist volumes 1 & 2
* Copies of Authentication Bureau Column The numismatist, (c.) 1991-2001 and 2007
* Clippings from coin world and numismatist news
* Pick up counterfeit coin detector, Bill Fivaz (pocket reference) TIP --> (You can pick these up on ebay. They offer many geniune dianostics for the key dates, including the 1916 D mercury dime and three legged buffalo. Once you know the geniune dianostics its much easier to authentication the altered mint marks or specifics. I got one from the class, a pocket reference from bill fivaz hand signed by him)
Other references :
* Misc counterfeit reports
* National collectors lab
* ANA cert. service
* I.B.S.C.C reports and bulletins recourse
* ANA Mediation service
* PNG Arbitration service
* US postal inspector (?? No idea on this one)
* Federal trade commission
* Legal action. (?? I think this section was on what to do if you had your coins stolen or if you had a counterfeit coin to give it over to the secret service. Not sure)
For Struck counterfeits:
* There are numberous methods used to produce
~ Die struck coins are superior in quality to cast methods
For cast counterfeits, some dianostics generally seen on these:
* pimples and pits (air bubbles)
* edge seams
* weight and diameter are sometimes off
Electrotypes:
Electrotypes are a soft impression in wax , they are then plated. Lots of ancient coins are done this way. They also often have an edge seam.
More about depressions:
~ Depressions have metal flow through them, bagmarks are shiny surrounding the bagmark.
The vast majority of spark erosion counterfeits are copper.
General counterfeit information:
The more counterfeits made the more loss of detail from that die; so the coin is therefore struck with more force to compensate. Gold coins often have the denticals and on the 1908 S and 1909 S indian cent.
Geniune dianostics for several key date coins and alterations:
1) The 1909 S VDB
Geniune specimens should have a die chip in the s, there is a deficient on upper loupe serif, paraellal sides on left. (?)
Check for tooling, scratches, displaced metal polishing or cleaning to conceal evidence
TIP!--> embossed mint marks are made by drilling a hole into the coin. Watch out for them.
2) 1937 D Buffalo Nickel
Here's a good way to remember the dianostics on a geniune unaltered buffalo nickel of this date.
"If the buffalo's pi**ing they legs missing"
1901 S 25 c -- Watch for seams around the mintmark.
1917 Type 1 25 c -- Watch out for re-cut lines
1932 D and S 25 c -- Check for seams stuck on coin
TIP! --> On authentication, you generally cannot deem a struck coin counterfeit with only one depression, generally you need other signs such as spikes from the denticals (Although about 3% of coins with spikes from the denticals are geniune) or multiple depressions.
* On the 1893 S mint alterations are most common.
* On the 1894 S $1 look for a die couge on the leg of the eagle. (on geniune pieces)
* On the 1895 silver dollar the date rises, usually the 5 rises the most.
~~ 1928 S $1 peace
Look for light die polish in rays, S mint marks on peace dollars usually sits in a depression, fat.
Counterfeit gold coins information
There are 2 types of fields on gold coins.
First,
The Flat Field Type:
The flat field type is on the :
$1 gold liberty, $2.5,$5,$10, and $20 liberty head and the $3 indian head
Flat field coins have denticals, cartwheel luster type.
Next,
The sculpted field type:
Indian head $10 gold and saint gaudens $20 gold
Dianostics for counterfeit pieces: Loss of fine detail, weak fat appearance in the letters, numbers, stars etc, denticals seperate, uneven. Known as "toothy" tool marks through the letters, field and numbers.
TIP! --> The instructor told me he was able to go on ebay and within 5 minutes find a counterfeit US gold coin from just the look of the coin. On this paticular coin, and on some counterfeit gold US coins, there is a halo or dishing effect on the transition of the field to the denticals. It is a bright circle around inside of the denticals.
Characteristics of geniune coins:
(Sometimes the best way to tell if a coin is counterfeit is to know the geniune characteristics. Here are a few of them)
1) Flat even fields
2) good luster and metal flow
3) clear, well formed denticals
4) fine details
5) good relief
6) fine die polish (counterfeits often show loss of detail everywhere)
7) Meets mint specifications for weight, diameter and metal content.
8) die cracks. These are seldon seen on counterfeits
9) denticals are sharp. (TIP! Some counterfeits also have fatty stars. See above)
10) A halo is a bright circle on edge of coin (see above)
Other charateristics of counterfeit gold:
1) Loss of relief
2) Raised bumps, ("Pimples")
~Interesting fact: There was once a infamous counterfeit who "signed" his work with the omega sign. No one knows if he ever was caught, but he counterfeited high relief 20 dollar eagles very well. He also counterfeited $3 indian princess gold. One way you can tell is to look for the omega symbol in the top of "R" on this $3 coin.
TIP! Rotate a counterfeit coin under a good light source to spot depressions
TIP! A linear depression is when lint gets between dies. These often are long, thin, with luster. (These are sometimes on geniune coins too, as well as other depressions)
TIP!It's harder to use the fields on the indian head for authentication due to the incuse design. (On the 2 1/2 and 5 dollar pieces). Instead, on geniune specimens, look for die polish lines in the recess of the neck. These are short parallel lines.. On counterfeit specimens, look in stars for toolmarks.
TIP! Die polish are fine lines over the entire coin. This is from when the dies were heavily polished at the mint.
TIP! $10 indians sometimes have depressions on the letters. That's a good place to look for them.
Contact marks are shiny, where as counterfeit depressions generally have luster in them, metal flow through them, and match the surface characteristics outside of the depression in realative to the depression. They also often have soft, rounded surfaces.
Regarding the 3 legged buffalo error, here are some pointers:
Brian said, "If the buffalo's pi**ing, they legs missing." referring to the stream of 'pee'
1. The leg is missing (due to it being polished off) but the roof is still visible.
2. There is a longer appendage (stream of 'pee') from the bison's belly, with a long, raised arc of "bumps" leading down to the ground
3. There is a "moth-eaten" appearance to the bison's hide, especially on the rear leg.
4. The E PLURIBUS UNUM over the bison's back is thinner and further away from the back.
(Note: These are all on GENIUNE examples, if you know what a geniune one looks like, anything but will look suspect.)
Here is a photo of the hoof 'cap'. Notice how it slopes down to the right. If it is straight, the coin is a counterfeit:
Source: Link
Ok, I hope this helps someone. And please, if you notice any mistakes, please point them out. I'm open to constructive criticism.
Overview of counterfeit detection:
Counterfeit coins are becoming more of a problem as time passes. It is all too apparant, and grading company slabs are even being targeted. Fakes can range from crude (cast copy), to excellent (transfer die struck). Many gold coins coming from the middle east are exceptional, and it is a rule to remember that some of the best counterfeits, if it looks too good to be true, it probably is.
In the summer of 2002, first brought to the attention in the magazine Coin World, a very strange error coin came. The existence of a 'mule' consisting of the obverse of a 1959-D cent and the reverse (wheat ears) of a cent from 1958 (or earlier). To Bob Campbell, a famous autheticator, the coin just didn't "look right", he said "Something about the coin just didn't seem right", later he said, "The fabric was there and everything pretty much looked correct, but it just felt wrong -- not a physical kind of 'feel' but more of a gut like feeling." Indeed, the coin looked too good. How could such a spectator error go unnoticed ? That's because the coin was a forgery, different from a counterfeit. Generally counterfeit coins are contempoary, they are mean't to be used in circulation. Where as a forgery, is made to fool numismatic experts and dealers.
More about the coin, it was actually made by infamous Mark Hofmann. He once said, "If I can produce something so correctly, so perfect that the experts declare it to be geniune, then for all practical purposes it is geniune. There is no fraud involved when I sell it."
In his book Numismatic Forgery, Charles M. Larson, who was the sergent at night when he worked at the prison which Mark Hofmann was sentenced to, talked and interviewed Hofmann several times. Hoffman told Charles that he used an ingenious method of creating dies using an electroplating process.
You can read more about Numismatic Forgery in Charles Book, Numismatic Forgery
A few rules of thumb:
Generally there are different types of creating counterfeit coins and how to spot them. Many times counterfeiters would actually melt down a very worn (but authentic) $20 double eagle to make several $1 gold coins, which have a high numismatic value relative to their intrinsic, or gold content. This way the gold used has the same fineness as geniune mint gold, as well as the proper alloy. (Because the worn $20 is a geniune coin, it can be purchased for less than fifty dollars over spot of the gold it contains.)
As a general rule, it is said that coins that are EF or lower, chances are it is geniune.
Overview of different counterfeit types:
Cast counterfeits:
Generally, cast counterfeits are the most poorly made. Often you will see blobs of metal through the letters or devices of the coin. Often times, as well they can be identified by a seam that runs about the outside edge of the coin. Casting can be made from plastic molds, using centrifugal force. Cast counterfeits, unlike transfer die high quality counterfeits, are often underweight and may use a different material (such as tin), instead of silver if the coin is a silver coin.
Electrotypes:
These are generally used by museums.They are made by impressing a geniune coin nito a soft substance and electroplating the negative impression, creating a positive shell. Generally the edge can give this away, as with cast counterfeits many electrotypes have a seam around the edge. Generally when "rung" electrotypes will not sound right, because of the process made.
Transfer dies:
These are the most common used and also the most deceptive.
The counterfeiters actually create a working die this time, but since they are using the same die all imperfections struck from those dies will go onto the coins. Sometimes there will be a blemish on the die, and the counterfeiter tries to remove it.
A typical struck counterfeit:
This leaves short, stubby lines on the finished coin called toolmarks. Alot of Indian head gold coins have toolmarks in the recess of the neck. Also since the counterfeiter is using the same die, there are things known as repeating depressions. The reason they are repeating is because any coin struck with that die will have the same imperfection. A geniune coin must be sacrificed as a host to make the transfer dies. Because the geniune coin used will have contact marks, the metal flows into the planchet creating what is known as depressions on the counterfeit coin.
High quality (probably middle eastern) struck counterfeits, all returned body bagged as counterfeit by PCGS.
These are small, often circular crators in the coin which often blend with the surrounding field, but because they were struck, they have luster inside them. Often a contact mark is shiny and does not blend in with the fields of the coin because the metal is disrupted.
It is said that the most common counterfeited coins are the ones collectors buy the most, because of demand. This is what Charles said in his book, Numismatic Forgery. For some reason, there are few counterfeit coins before 1840.
A counterfeit gold coin (probably another base metal) in a counterfeit PCGS slab. This was found on ebay from a seller oversea's.
Counterfeiting slabs are becoming more of a problem and NGC has taken actions with this in their slabs. PCGS has also taken action, issuing a warning to be careful of counterfeit PCGS slabs, and how to spot them.
Spark Erosion Counterfeits:
These are generally easy to detect because how they are made.
In this process, A geniune coin is put in an electrolyic bath where the coin faces the counterfeiter's die steel. An electrical current spark is charged t hrough the coin so that the spark goes across the shortest gap between the coin and die, creating the coin's design onto the steel die
Often times these coins are heavily pitted because of this process..so the counterfeiter's polish the dies to make up for this. These can be detected by their lumpy devices, and are often found on small type coins like cents and dimes.
Some rules of thumb:
Because of the transfer die process, many gold coins use this. Also, because a geniune host coin is used and a crude die is made, called an impact die, there is generally loss of detail on the counterfeit coin.
A good thing to do is look at many geniune coins in a paticular series. Once you know what a geniune coin looks like, in general, counterfeits become much easier. Generally geniune coins have sharp, crisp letters and devices, numbers as well. Weak fatty letters and devices are a dead giveaway the coin is counterfeit. Please remember that generally you need many different attirbutes to determine a coin throughoutly counterfeit, for example if you just find a depression or two on the coin, this is not enough to deem it counterfeit. Depressions can also be mint made, but often they do not have the luster that a counterfeit coin has.
Another thing to look for on counterfeit gold coins are spikes from the denticals or devices, such as stars of the coin. I'm actually not sure what spikes are caused from, but I know that spikes along from the denticals ont he coin are not enough to deem it counterfeit; as discussed earlier because sometimes geniune coins have them too. According to expert numismatic authentication expert Randy Campbell, about 3% of geniune coins have them.
Color is another thing to look for on counterfeit coins. Generally sometimes, the color is just "off" and it doesn't look right. This can only come with years of looking at geniune coins and knowing your series well. For example, branch mint coins struck in Charlotte, North Carolina usually have a red hue, where coins minted in Dahlonega, Georgia, or new orleands, and also Louisiana often have a greener cooler. Note: I have read in an issue of Numismatic News that coins from the southern mints, such as Dahlonega and new Orleans, the coins often have a lighter color, and this is because these coins have a higher silver content in them, mixed with the gold alloy produces a different color. This seems to contrast with what I posted earlier...but I believe it is the correct one.
On cast counterfeits, often the coin is not the correct weight weight, so you may need to weigh them. Many transfer die struck gold coins are the proper weight and fineness (because of , in some cases, a melted double eagle makes several gold dollars)
Many counterfeiters do not take the time, unlike the mint, to polish their dies. Therefore lots of die polish relevent in protected area's of the coin, are a good sign or a possible sign it is geniune
Often times what counterfeiters will do is buy a blank planchet, which the mint has made (on accident) (such as a silver dime planchet for a 16-D mercury) and use that to create the counterfeit coin.
I hope this information helps learning more about counterfeits.
The key is to look at as many coins certified by the Top TPG's, that are geniune, so you know anything that doesn't look geniune is suspect.
Credit goes to Numismatic Forgery, United States Gold counterfeit detection guide by Bill fivaz, and the guide to grading and counterfeit detection by PCGS.
Counterfeit dies made from chinese counterfeiters:
Excerpt from Bill Fivaz book, on counterfeit gold. Notice the linear depressions (which is from when something gets stuck on the die and is struck, leaving a depression), and the luster within the other depressions:
(Note: The following are notes taken from my ANA counterfeit detection seminiar I took at the ANA Phoenix show with teacher Brian Silliman. They are filled with many tips and tricks, I hope you enjoy them)
Notes from authentication, grading, and conservation class taken at the ANA national money show pre-convention seminiar in march, in phoenix.
Authentication:
Contempoary counterfeits are circulated
Q: What are altered coins?
~ Date alteration:
A: One or more of the digits are "altered" so the coin can be passed as a more valueable date.
TIP! --> *First coins made by counterfeit dies look too prooflike (PL), unreal. Worn down counterfeit coins made by counterfeit does look more deceiving.(Worn out dies)
TIP! --> Bay Area counterfeits -- (Look up)
~Mint mark alteration:
* The addition or removal of a mintmark to produce a more valueable specimen.
Alterations:
Form of a counterfeit coin. Note: This is not the same as surface alteration on a coin.
Depressions. --> Depressions are contact marks on an orgininal coin used as a host (sacrificed) on a counterfeit die to make counterfeit coins.
Interesting note -->
Struck counterfeits are most often seen on gold coins.
Alterations are most commonly seen on all key dates or mintmarks and on most better dates.
TIP!--> Take the How To Detect Counterfeit and Altered US coins ANA correspondence course.
TIP! --> Most struck counterfeits are uncirculated.
Recommend references for further reading:[list][*]ANA Reprints from the numismatist volumes 1 & 2
* Copies of Authentication Bureau Column The numismatist, (c.) 1991-2001 and 2007
* Clippings from coin world and numismatist news
* Pick up counterfeit coin detector, Bill Fivaz (pocket reference) TIP --> (You can pick these up on ebay. They offer many geniune dianostics for the key dates, including the 1916 D mercury dime and three legged buffalo. Once you know the geniune dianostics its much easier to authentication the altered mint marks or specifics. I got one from the class, a pocket reference from bill fivaz hand signed by him)
Other references :
* Misc counterfeit reports
* National collectors lab
* ANA cert. service
* I.B.S.C.C reports and bulletins recourse
* ANA Mediation service
* PNG Arbitration service
* US postal inspector (?? No idea on this one)
* Federal trade commission
* Legal action. (?? I think this section was on what to do if you had your coins stolen or if you had a counterfeit coin to give it over to the secret service. Not sure)
For Struck counterfeits:
* There are numberous methods used to produce
~ Die struck coins are superior in quality to cast methods
For cast counterfeits, some dianostics generally seen on these:
* pimples and pits (air bubbles)
* edge seams
* weight and diameter are sometimes off
Electrotypes:
Electrotypes are a soft impression in wax , they are then plated. Lots of ancient coins are done this way. They also often have an edge seam.
More about depressions:
~ Depressions have metal flow through them, bagmarks are shiny surrounding the bagmark.
The vast majority of spark erosion counterfeits are copper.
General counterfeit information:
The more counterfeits made the more loss of detail from that die; so the coin is therefore struck with more force to compensate. Gold coins often have the denticals and on the 1908 S and 1909 S indian cent.
Geniune dianostics for several key date coins and alterations:
1) The 1909 S VDB
Geniune specimens should have a die chip in the s, there is a deficient on upper loupe serif, paraellal sides on left. (?)
Check for tooling, scratches, displaced metal polishing or cleaning to conceal evidence
TIP!--> embossed mint marks are made by drilling a hole into the coin. Watch out for them.
2) 1937 D Buffalo Nickel
Here's a good way to remember the dianostics on a geniune unaltered buffalo nickel of this date.
"If the buffalo's pi**ing they legs missing"
1901 S 25 c -- Watch for seams around the mintmark.
1917 Type 1 25 c -- Watch out for re-cut lines
1932 D and S 25 c -- Check for seams stuck on coin
TIP! --> On authentication, you generally cannot deem a struck coin counterfeit with only one depression, generally you need other signs such as spikes from the denticals (Although about 3% of coins with spikes from the denticals are geniune) or multiple depressions.
* On the 1893 S mint alterations are most common.
* On the 1894 S $1 look for a die couge on the leg of the eagle. (on geniune pieces)
* On the 1895 silver dollar the date rises, usually the 5 rises the most.
~~ 1928 S $1 peace
Look for light die polish in rays, S mint marks on peace dollars usually sits in a depression, fat.
Counterfeit gold coins information
There are 2 types of fields on gold coins.
First,
The Flat Field Type:
The flat field type is on the :
$1 gold liberty, $2.5,$5,$10, and $20 liberty head and the $3 indian head
Flat field coins have denticals, cartwheel luster type.
Next,
The sculpted field type:
Indian head $10 gold and saint gaudens $20 gold
Dianostics for counterfeit pieces: Loss of fine detail, weak fat appearance in the letters, numbers, stars etc, denticals seperate, uneven. Known as "toothy" tool marks through the letters, field and numbers.
TIP! --> The instructor told me he was able to go on ebay and within 5 minutes find a counterfeit US gold coin from just the look of the coin. On this paticular coin, and on some counterfeit gold US coins, there is a halo or dishing effect on the transition of the field to the denticals. It is a bright circle around inside of the denticals.
Characteristics of geniune coins:
(Sometimes the best way to tell if a coin is counterfeit is to know the geniune characteristics. Here are a few of them)
1) Flat even fields
2) good luster and metal flow
3) clear, well formed denticals
4) fine details
5) good relief
6) fine die polish (counterfeits often show loss of detail everywhere)
7) Meets mint specifications for weight, diameter and metal content.
8) die cracks. These are seldon seen on counterfeits
9) denticals are sharp. (TIP! Some counterfeits also have fatty stars. See above)
10) A halo is a bright circle on edge of coin (see above)
Other charateristics of counterfeit gold:
1) Loss of relief
2) Raised bumps, ("Pimples")
~Interesting fact: There was once a infamous counterfeit who "signed" his work with the omega sign. No one knows if he ever was caught, but he counterfeited high relief 20 dollar eagles very well. He also counterfeited $3 indian princess gold. One way you can tell is to look for the omega symbol in the top of "R" on this $3 coin.
TIP! Rotate a counterfeit coin under a good light source to spot depressions
TIP! A linear depression is when lint gets between dies. These often are long, thin, with luster. (These are sometimes on geniune coins too, as well as other depressions)
TIP!It's harder to use the fields on the indian head for authentication due to the incuse design. (On the 2 1/2 and 5 dollar pieces). Instead, on geniune specimens, look for die polish lines in the recess of the neck. These are short parallel lines.. On counterfeit specimens, look in stars for toolmarks.
TIP! Die polish are fine lines over the entire coin. This is from when the dies were heavily polished at the mint.
TIP! $10 indians sometimes have depressions on the letters. That's a good place to look for them.
Contact marks are shiny, where as counterfeit depressions generally have luster in them, metal flow through them, and match the surface characteristics outside of the depression in realative to the depression. They also often have soft, rounded surfaces.
Regarding the 3 legged buffalo error, here are some pointers:
Brian said, "If the buffalo's pi**ing, they legs missing." referring to the stream of 'pee'
1. The leg is missing (due to it being polished off) but the roof is still visible.
2. There is a longer appendage (stream of 'pee') from the bison's belly, with a long, raised arc of "bumps" leading down to the ground
3. There is a "moth-eaten" appearance to the bison's hide, especially on the rear leg.
4. The E PLURIBUS UNUM over the bison's back is thinner and further away from the back.
(Note: These are all on GENIUNE examples, if you know what a geniune one looks like, anything but will look suspect.)
Here is a photo of the hoof 'cap'. Notice how it slopes down to the right. If it is straight, the coin is a counterfeit:
Source: Link
Ok, I hope this helps someone. And please, if you notice any mistakes, please point them out. I'm open to constructive criticism.
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Comments
I'm looking forward to seeing what else you add, and I will try to post some counterfeits I have as examples for you.
<< <i>WOW, great post so far
I'm looking forward to seeing what else you add, and I will try to post some counterfeits I have as examples for you.
Thanks, it still has some errors I need to get wringed out. Mostly in the notes section...I had taken the ANA seminar in counterfeit detection (only a 1 day course) and I had to jot down notes fast....the other's I had done some research on and based on my knowledge.
I appreciate offering some counterfeit pictures...that would make this thread even better.
Note: I've added a special section for the alteration of a regular buffalo into the rare error '3 legged' buffalo.
BS&T
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