1857-S Double Eagle - 1857-S $20 PCGS AU55. This Choice AU, Western branch mint 1857-S double eagle, in an older type PCGS holder, has outstanding eye-appeal because of its original mint luster and color. The light and dark yellow gold that are highlighted by creamy mint luster confirm the coins originality. The strike is strong with full details on Libertys hair, the centers of the stars, and the design details of the reverse, especially the eagle. The surfaces are clean for the grade with no notable abrasion marks or other distractions.
 
The San Francisco Mint opened in 1854 because of the need to coin gold resulting from the California Gold Rush. In the West there was an abundance of gold bullion, nuggets and dust; however, there was also an acute shortage of circulating coinage. Congress authorized this mint to relieve the shortage and coin silver and gold and because transportation of bullion to Philadelphia was time consuming and hazardous. Because of its proximity to the Gold Rush area, San Francisco was chosen as the site of the new mint.  In 1874 it moved into a new building called the Old United States Mint or the Granite Lady. It is one of the few structures that survived the earthquake of 1906. It remained in service as a mint until 1938, when the present facility opened.

In its first year of operation the Mint made four million dollars in gold coins from bullion. The second building, the Old United States Mint, was designed by Alfred B. Mullett in Greek Revival style. It was built in an E-shape with a central pediment portico. There was a completely enclosed courtyard that had a well. It was these features that saved it in the fire that resulted from the earthquake of 1906. The building was situated on a concrete and granite foundation that was made to prevent tunneling into its vaults. In 1906 there was $300 million, a third of the United States gold reserves, in its vaults. Frank Leach and his men worked heroically to successfully preserve the building and the bullion. The mint was able to resume service and operated until 1937. It was designated a National Historic Landmark in 1961.

Since most of the building was made of sandstone, the nickname of The Granite Lady is a misnomer. Only the basement was made from granite. It was opened to visitors in 1993 and sold to the City of San Francisco for one dollar in 2003 for use as the Museum of the City of San Francisco.

Designed by James B. Longacre, the double eagle shows a Liberty head facing left, wearing coronet inscribed LIBERTY. Her hair is tightly tied in the back with two loose curls hanging down her neck to the end of the truncation. She is surrounded by thirteen six-pointed stars with the date below. Dentils are near the edge on both sides of the coin. The reverse shows a heraldic eagle with elaborate ribbons on both sides of the shield extending from the top corner down to the eagles tail feathers. The ribbons are inscribed, on the left E PLURIBUS and UNUM on the right. The ribbons were added to the design to symbolize the denomination since this was the first twenty dollar coin. There is an oval of thirteen stars above the eagles head and an arc of rays from wing tip to wing tip behind the upper half of the oval. UNITED STATES OF AMERICA is in an arc above the eagle, and the denomination TWENTY D. is below. The mintmark is between the tail feathers and the N of TWENTY.