Mint Error Coin Chronicles: Brockage

Numismatic Guaranty Company® (NGC®) is the world’s leading authority on mint errors, a popular segment of numismatics. In Mint Error Coin Chronicles, we take an in-depth look at a specific kind of mint error. This month’s topic is the Brockage error.

After a coin is struck by its dies at the mint, it is supposed to be ejected so that it doesn't interfere as the dies strike the next planchets. If this doesn't happen, a Brockage error can occur. When a wayward coin comes between the die and a subsequent planchet, the coin that was supposed to have been ejected can instead transfer an inverse (mirror) version of its die to the planchet.

Take a look at this India Rupee. The side that is holdered toward the back is the typical obverse of an India Rupee struck between 1911 and 1936. On the other side, the strike of the design is noticeably fainter, the letters are inverted and King George V is facing to the right instead of to the left. The design on this side of the coin was imparted by another Rupee. (This particular coin is part of a Heritage Auctions sale in March 2024.)

India (1911-36) Rupee graded NGC Mint Error AU 50 - Brockage on Reverse Click images to enlarge.

Not only will the side with the Brockage be mirrored but it will also be incuse. The design elements that would normally rise above a coin's fields, such as the letters and the bust, will instead appear sunken into the surface. This is because, unlike the coin imparting the Brockage error, the dies have these design elements sunken into their surface.

Brockage errors are highly interesting and can be worth hundreds of dollars. Below are some examples of NGC-certified coins with this particular mint error that were sold recently through Heritage Auctions:

Germany (1846-46) Frankfurt 3 Kreuzer graded NGC Mint Error MS 67 - Partial Collar with Obverse Brockage. Realized $348 in August 2023. Click images to enlarge.

Haiti 1846//AN 43 2 Centimes graded NGC Mint Error XF 40 BN - Obverse Brockage. Realized $456 in March 2023. Click images to enlarge.

US Jefferson Nickel graded NGC Mint Error MS 65 - Struck 60% Off Center with Obverse Brockage. Realized $139 in December 2022. Click images to enlarge.

Germany (1874-76)E 10 Pfennig graded NGC Mint Error MS 62 - Obverse Brockage. Realized $169 in June 2023. Click images to enlarge.

Turkey AH1255 Para graded NGC Mint Error MS 62 - Reverse Brockage, part of a two-coin lot that realized $169 in January 2024. Click images to enlarge.

Other Mint Error Coin Chronicles Articles:

• Broadstrikes
• Partial Collars
• Rotated Dies Error
• Transitional Errors