Diagnostic Controls & Presets Visual Struck Error Studio • $200–$2,500+ Value
Diagnostic Forensic Readings
Forensic Attribution Diagnostic
Real-time metallurgical and die variety cross-examination verified against certified populations.
Technical Breakdown: Physics, Metallurgy & Die Diagnostics
Multi-Planchet Feeding Dynamics
An indented error occurs when two blank planchets enter the coining chamber simultaneously, resting partially overlapped across each other when the dies close:
Because the overlapping blank prevents the upper die from contacting the underlying metal, the resulting coin features a smooth, unstruck, mirror-concave crater matching the curved curvature of the second planchet.
Indented Planchet vs Brockage Diagnostics
The crucial numismatic distinction depends on the striking state of the overlapping coin:
Brockage errors command approximately double the collector value of plain indented planchets because the sunken crater contains complete, backwards, mirror-image design elements.
Documented Benchmark Auction Records
Heritage Auctions Signature Error Sale. Dramatic half-moon smooth crater indentation with full date and mint luster intact on the exposed coin field.
Stack's Bowers Rarities Auction. Phenomenal incuse mirror portrait of Lincoln impressed backwards into the uncoined depression.
GreatCollections Certified Auction. Pristine uncirculated gem showing deep planchet compression and outward centrifugal expansion.
Frequently Asked Questions
What is an 'Indented Planchet' coin error?
An indented planchet error occurs when two blank planchets enter the coining chamber at the same time, partially overlapping. When struck, the top blank is pressed into the bottom blank, leaving a deep, smooth, circular crater where the two coins touched.
What is the difference between an indent and a brockage?
An indent is caused by an un-struck blank planchet, leaving a completely smooth crater. A brockage is caused by an already-struck coin, which presses its design into the blank, creating an incuse (sunken) and backwards (mirror-image) design inside the crater.
Does an indented coin weigh less than a normal coin?
No! An authentic indented coin has its full normal weight because none of the metal was clipped or cut away. The metal was simply displaced outward under the hydraulic pressure of the coining dies.
How much are indented planchet error coins worth?
Values typically range from $150 to $350 for Lincoln Cents and Roosevelt Dimes, and $500 to over $1,200 for Washington Quarters and Half Dollars.
Does the position of the date matter on indented coins?
Yes! If the coin's date is located on the exposed, fully struck portion and remains clearly legible, the coin is worth significantly more than an undated specimen.
Can you fake an indented coin with a shop vise?
Yes, counterfeiters sometimes press two coins together in a vise. Authentic mint errors feature dramatic metal displacement, unstruck smooth fields with original mint luster in the crater, and outward curvature.
Will PCGS and NGC certify indented planchets and brockages?
Yes, both PCGS and NGC regularly attribute and certify indented planchets, specifying the exact percentage of indentation directly on the label.