NGC Counterfeit Detection Methods 3 — Questions and Answers
Question 1: NGC's in-house authentication process includes 'fingerprinting' coins by examining:
- Owner fingerprints left during handling
- Die characteristics unique to each working die pair (Correct answer)
- The serial number stamped on the holder
- Vault storage records from the mint
Correct answer: Die characteristics unique to each working die pair
NGC authenticators identify coins by matching unique die characteristics — scratches, clashes, and hub doubling patterns — to known genuine examples.
Question 2: Which type of counterfeit is created by chemically altering a genuine coin of lower denomination or date to imitate a rarer, more valuable issue?
- Cast counterfeit
- Altered coin (Correct answer)
- Tooled counterfeit
- Electrotype
Correct answer: Altered coin
An altered coin is a genuine coin that has been physically or chemically modified — such as changing a date or mintmark — to simulate a rarer variety.
Question 3: On counterfeit Saint-Gaudens Double Eagles, the high-relief portrait fields most often reveal fakery through:
- Correct die flow lines running toward the rim
- Porous or granular surfaces from casting porosity (Correct answer)
- Missing designer's initials A.A.S.
- Overly deep reeding on the edge
Correct answer: Porous or granular surfaces from casting porosity
Cast counterfeits of Saint-Gaudens Double Eagles show porosity (tiny pits and rough texture) in the open fields that betray their casting origin.
Question 4: What is the primary purpose of examining a coin's 'luster' when detecting counterfeits?
- To confirm the coin has not been cleaned with abrasives
- To verify the metal's reflective properties match genuine mint striking
- To check for artificial toning applied to hide tooling
- Both B and C (Correct answer)
Correct answer: Both B and C
Genuine mint luster results from die flow lines created during striking; examining luster reveals both whether the coin was struck correctly and whether artificial toning hides alterations.
Question 5: Which famous coin series has been extensively counterfeited using genuine but common-date examples with added or altered mintmarks?
- Lincoln Memorial Cents (1959-2008)
- Buffalo Nickels (1913-1938) (Correct answer)
- Washington Quarters (1932-1964)
- Jefferson Nickels (1938-present)
Correct answer: Buffalo Nickels (1913-1938)
Buffalo Nickels are frequently altered by adding or moving mintmarks (especially to create the rare 1916 Doubled Die or key-date 'D' and 'S' issues).
Question 6: An electrotype reproduction of a rare coin differs from other counterfeits primarily because:
- It is legal to produce and sell as a collectible
- It is made by depositing metal electrolytically over a mold of the original coin (Correct answer)
- It always contains the correct silver or gold alloy
- It bears an 'E' mintmark indicating electrotype origin
Correct answer: It is made by depositing metal electrolytically over a mold of the original coin
Electrotypes are made by electroplating metal onto a mold taken from a genuine coin, producing a thin-shell replica that is hollow or filled.
Question 7: NGC uses which technology to create a permanent digital record of a coin's unique surface characteristics for future authentication?
- PCGS CoinFacts database
- NGC Registry photographic archiving (Correct answer)
- NumerisMatch digital die-mapping system
- Blockchain NFT tokenization
Correct answer: NGC Registry photographic archiving
NGC's Registry maintains high-resolution photographic records of certified coins, allowing future comparison of surface characteristics to detect swaps or forgeries.
NGC Counterfeit Detection Methods 3
NGC's in-house authentication process includes 'fingerprinting' coins by examining: