United States Mint officials may refer to one of the final steps in the production of the specially produced Sacagawea dollars given to sculptor Glenna Goodacre as "washing/cleaning," but those in the metal finishing industry affirm the process constitutes post-strike burnishing.
Controversy has swirled over the finish created on the 5,000 2000-P Sacagawea dollars presented April 5, 2000, to Goodacre as compensation for her Sacagawea dollar obverse design and whether the planchets were pre-burnished and the coins post-burnished.
Metal-finishing industry sources conclude that based on the Mint's explanation of the steps purportedly followed in making the Goodacre dollars - presumably the same followed for Uncirculated Mint set strikes - the dollars were both pre-burnished and post-burnished. The post-strike burnishing is what is being credited with giving the majority of the Goodacre pieces a glossy surface and sent collectors clamoring to obtain specimens.
Coin World's lead story on Page 1 of its March 26 issue, based on a Mint document submitted as part of the Department of Justice's lawsuit against a private mint, noted that the Mint considers the step some consider post-striking burnishing to be "washing/cleaning."
While presenting an explanation for the handling of the Goodacre dollars, the Mint's information doesn't address the purported post-strike burnishing of the 2000-D Sacagawea dollars incorporated in 75,000 Millennium sets. These coins are also considered to have received special treatment, but possibly with a different post-striking burnishing compound used.
Metal-finishing experts consider the use of burnishing compounds with agitation - be it rotating, tumbling or vibrating - along with media such as steel pellets or even dried corn cobs to constitute "burnishing" because it alters the surface of the metal.
The noticeable differences in the surface texture of the Goodacre dollars as compared to Uncirculated Mint set dollars - which, according to the Mint document, are supposed to have received the same treatment - and dollars struck for circulation has pushed the secondary market value of the Goodacre dollars over the $800 level. All of the 5,000 coins delivered to Goodacre have been encapsulated, but not graded, by Independent Coin Grading Company.
Goodacre has already sold half of the encapsulated coins to a numismatic distributor, with no immediate plans to market the remainder.
ICG officials have held steadfast in their convictions that the Goodacre dollars were subjected to a post-strike burnishing, eliminating them from being encapsulated with a grade, but still highly desired by collectors. The position has put them at odds with ANACS, which has crossed over Goodacre dollars into ANACS holders with grades based on the premise there was no post-strike burnishing.
The dispute appears to be boiling down to a game of semantics.
In January, Coin World published an article by ICG president Keith Love and senior numismatist J.P. Martin in which they revealed that ICG had found approximately 120 unburnished, Type 1 Goodacre coins.
Love said: "The comparison of the Type 1 Goodacre dollars with the post-strike burnished Type 2 coins proved certain facts about the process used in the production of these coins. One such finding came by examining the area under the baby's wrapping at approximately 7 o'clock on the obverse. A small area of unstruck planchet on these unburnished Type 1 coins, revealed that the planchet was in fact burnished before striking. On the Type 1 coins this area contrasts with the entire struck area of the coin."
Mint officials late in 2000 admitted that all of the Sacagawea dollars - coins produced for circulation, Uncirculated Mint sets, Proofs and the Goodacre coins - had the planchets burnished before striking. It wasn't until Coin World obtained from a federal lawsuit the first week of March a copy of a Dec. 14, 2000, declaration by the Philadelphia Mint's numismatic division chief James Smith that the complete process was divulged.
On March 8, a few days after obtaining Smith's declaration, the U.S. Mint provided - after months of questioning by Coin World - charts outlining, but not explaining, the production steps followed in manufacturing Sacagawea dollars for circulation and Uncirculated Mint set dollars.
The difference in the production steps is not apparent until the steps after the coins are struck, and it is here where the controversy begins.
In both processes, blanks are first punched out of coils of manganese-brass clad strip. The blanks are forced through an upsetting mill that places a raised rim on the coins. The blanks, which are now planchets, are then sent through the annealing process in a rotary furnace to temper them to the point of hardness for proper striking on the coinage presses.
The planchets are subjected to washing and drying processes before being burnished. Here, the burnish process uses stainless steel balls or pellets agitated within a centrifugal unit filled with chemical burnishing compounds to scrub the surfaces of the planchets to remove oxides and contaminants. The planchets are then placed in a vibrating finishing dryer with heated corncob to absorb residual moisture.
The planchets are then struck once on the coinage press. Uncirculated Mint set coins are struck on a Grabener press striking horizontally at a slow speed and adjusted pressure. Those struck for circulation are produced at high-speed on a Schuler press striking horizontally, with the striking pressure fluctuating with the thickness of the planchets.
The coins for circulation are ready for inspection, final packaging and shipment. The Uncirculated Mint set coins, and purportedly the Goodacre dollars, undergo a "washing/cleaning" cycle and second drying cycle.
During the washing/cleaning cycle, the Mint set coins are submerged in a solution that includes alkaline burnishing compounds for corrosion inhibition and to remove stamping oils. The coins, still fresh with the burnishing solution, are then put through a second drying procedure with vibrated, heated corncob to remove moisture and eliminate water spots.
There is no explanation given as to how long the struck coins were subjected to the final steps in the process and how that length of time can affect the type of surface that will finally result.
Metal-finishing sources indicate the burnishing of metal to improve the surface is not just through mechanical or chemical means, but both working in tandem. The steel balls, according to sources, will leave depressions and peaks in the metal, resulting in a flat surface that is not bright when subjected to a light source.
By incorporating the chemical burnishing compounds, the peaks can be bent over, not cut off, so when the surface is exposed to light, the surfaces will exhibit brilliance.
Smith admits in his court declaration that after the Uncirculated Mint set Sacagawea dollars are struck, they are immersed in a solution that includes L-980, a general purpose alkaline burnishing compound. After an unspecified period, the struck coins are placed in an open-tough air dryer where they are vibrated with heated corncobs.
"Remember this is while the coins have the L-980 burnishing compound on them," says ICG's Love. "Those familiar with polishing will know that corncobs alone are excellent for polishing silver. Corncobs are also excellent drying agents as they will absorb up to 16 times their own weight. The combination of this vibration system, corncobs and L-980 (all post-striking) is what provided the Goodacre coins with polished surfaces.
"The bottom line is the Goodacre coins are different, not slightly different, not within tolerance standards for 'looks' for production strikes or Mint sets, but obviously enough for children to detect. Thousands of collectors and dealers see the differences with their own two eyes. Different surfaces mean different production procedures," Love said.
