Mintage:
Circulation strikes: Unknown (estimated 180,000)
Proofs: Unknown

Designer: Albert Küner or Ferdinand Gruner

Diameter: ±34 millimeters

Metal content:
Gold - 90%
Silver and Copper - 10%

Weight:  ±33.4 grams

Edge: Reeded

Mintmark: None

Notes:
"The discovery of gold in California at the end of the 1840s attracted people from all walks of life to the west coast. In the sea of speculators, military personnel, and vagabonds that crossed the frontier to make their fortune, one man should stand out in the minds of numismatic scholars. Through his position as United States Assayer, Augustus Humbert served as the federal government's representative in the world of private mints that served Gold Rush California. After his arrival in San Francisco on January 30, 1851, Humbert worked with Moffat & Co. as head of the federal government's United States Assay Office. He remained with the firm through the end of the year and, following the continuance of the contract under the firm of Perry, Curtis, & Ward, continued in his original capacity for the United States Assay Office of Gold. During his tenure with these two firms, Humbert had the honor and responsibility of not only producing his own coins for circulation, but of assaying the coins produced by numerous other private ventures such as Dubosq & Co. and Dunbar & Co.
Despite Humbert's expertise and the quality of the coins that he released into circulation, few notables in Washington believed that the United States Assay Office in San Francisco was more than just a temporary measure. But Congress authorized a branch mint for California on July 3, 1852. With the anticipated opening of this facility close at hand, the United States Assay Office of Gold ceased operations on December 14, 1853. The abundance of red tape, however, delayed the opening of the San Francisco Mint until April 3, 1854. As there were no private firms producing gold coinage at this time and the remaining eagles, double eagles, and slugs from the United States Assay Office of Gold were too few in number, California entered a disastrous period of financial upheaval. In an attempt to alleviate this strain, local banks and merchants contacted John Glover Kellogg, a native of Onondaga County, New York and a former employee of the United States Assay Office. After he received an endorsement of integrity from Curtis, Perry, and Humbert, Kellogg agreed to issue gold coinage. On February 9, 1854, the first double eagles emerged from dies that Albert Kuner modeled closely after the identical federal denomination. Kellogg & Co. continued to issue double eagles through the end of 1855, at which time the improved operations of the San Francisco Mint rendered private coinage unnecessary.
While a few Uncirculated double eagles from Kellogg & Co.'s 1854 delivery exist from the Thayer County hoard, numismatists must consider the present specimen striking as the finest representation of the firm's coinage. Struck from a carefully prepared planchet, Kellogg produced this unique specimen before his firm inaugurated business strike coinage. Whether he presented the coin to Humbert as an example of his firm's workmanship or as a token of gratitude for his aforementioned endorsement, we do not know."
-excerpted from Heritage Numismatic Auction, Inc.'s October 1999 "Heritage/eBay E-Fair" sale, Lot 6254

Images courtesy of Heritage Numismatic Auctions

Varieties:
Kagin 1 - Rare
Kagin 1a - Very Scarce
Kagin 1b - Rare
Kagin 2 - Very Scarce

Significant examples:
PCGS Specimen-68.  Ex - Augustus Humbert - Captain Andrew C. Zabriskie (Henry Chapman, 6/1909) - Colonel James W. Ellsworth (Wayte Raymond, 1923-1926) - Garrett II (Bowers & Ruddy, 3/1980), lot 908 at $230,000 - Joseph Flynn (1982) - 1982 ANA Sale, lot 2928 at $58,000 - Casey Noxon/Larry Hanks to Hugh Sconyers collection (1983) - Ed Milas/Rarcoa (1985) - private collection - Heritage Numismatic Auctions, Inc. October 8, 1999 "Heritage/eBay E-Fair Auction, lot 6254, not sold - offered by Hanks & Associates at the January 2000 Florida United Numismatists Convention for $1,250,000

Recent offerings:
About Uncirculated.  Ex - Stack's "65th Anniversary Sale", October 17-19, 2000, Lot 1971, "K. 1b, Short Arrows"

Very Fine.  Ex - Stack's "65th Anniversary Sale", October 17-19, 2000, Lot 1970, "K.1 (R-5), Short Arrows"

Sources and/or recommended reading:
"Walter Breen's Complete Encyclopedia Of U.S. And Colonial Coins" by Walter Breen

"Private Gold Coins and Patterns of the United States" by Donald H. Kagin