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Extremely Rare 1853 U.S. Assay Office Twenty, .884 Thous., MS63
Single Finest at PCGS and Tied for Finest Certified

1853 $20 Assay Office Twenty Dollar, 884 Thous. MS63 PCGS. K-17, Low R.7. Nitric acid and sulfuric acid are among the few known chemical substances that can dissolve gold, or "part" it from the various alloys with which it is normally bonded when found in its natural state. The lack of parting acids was a chronic problem both for the U.S. Assay Office of Gold, as well as later for the fledgling San Francisco Mint.
In October 1852 the San Francisco customs collector received a letter from the Treasury Department, essentially telling him to accept only U.S. federal gold coins that conformed to the Mint Act of June 25, 1834--.900 fine gold. California gold coins of any other standard were essentially devalued, as they were of lesser commercial utility. The concern in Washington was that nonconforming gold coins would enter world commerce, damaging U.S. prestige overseas. In reality, the Assay Office pieces of lesser fineness were actually compensated by assayer Augustus Humbert with an increased weight--a fact that the Washington insiders likely did not know.
The local merchants met with the customs collector, absolving him of personal responsibility so he could accept .900 fine coins without the proper copper alloy mix, something that was essentially unproducible in California at the time.
But the parting acids were on backorder, and Humbert made the decision to strike emergency ten and twenty dollar pieces, first with the .880 fineness and then with the .884 fineness, as Kagin says "in total defiance of the August 31, 1852, law. [Humbert] hesitated as long as possible, and then commenced striking the lower fineness coins from February 23 to March 1, 1853. The new parting acids arrived before too many pieces were struck and immediately the .884 THOUS. pieces on hand were remelted and coined into .900 THOUS. coins."
That remelting accounts for the extreme rarity of the few .884 THOUS. survivors, and the present piece is not only the single finest certified at PCGS, it is one of only three Mint State pieces graded at that service (12/07) along with one MS60 and one MS62 piece. NGC has certified seven pieces, the finest also an MS63. The surfaces are a deep greenish-gold, with a somewhat prooflike appearance and numerous small contact marks consistent with the grade. This coin presents a fine opportunity for some fortunate collector to obtain what is--barring the fifty dollar slugs--the rarest of the U.S. Assay Office pieces. Listed on page 355 of the 2008 Guide Book. (NGC ID# ANHC, PCGS# 10010)

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Auction Dates
January, 2008
9th-12th Wednesday-Saturday
Internet/Mail/Phone Bidders: 5
Lot Tracking Activity: N/A
Page Views: 1,858

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