Smithsonian Preserves National Numismatic Collection Through NGC Encapsulation of International Coins
The Smithsonian’s National Museum of American History today announced the completion of a second project to increase the long-term preservation of the National Numismatic Collection housed at the museum through protective coin holders. The 100 coins recently encapsulated are some of the rarest and most important world coins in the museum’s collection. The encapsulation allows greater access to coins while ensuring their protection.
The project is a collaboration between the museum and Numismatic Guaranty Corporation, which started with a pilot project in 2008 to encapsulate 200 of the most prized coins in the museum’s American coin collection. NGC donated their services and provided the materials necessary to rehouse the coins.
“These coins are popular for scholarly study, and now they can be handled safely through the generosity of NGC,” said John Gray, director of the museum. “We are pleased to be able to provide protection for our objects while at the same time extending access to the research community.”
“NGC is privileged to work with the museum to help alleviate a collections management challenge,” said Mark Salzberg, chairman of NGC. “We are honored to make the full breadth of our expertise and our services available to the NNC and the greater numismatic community.”
Encapsulating world coinage is challenging because the size of each object varies greatly. Oversized holders were customized to larger objects and new EdgeView technology makes it possible to see the coin edge. The EdgeView holder is made of inert mold-injected resin and the label, identifying the coin in it, is printed on acid-free paper. The standard NGC holder is roughly 60 mm wide by 85 mm tall. It can accommodate coins up to 45 mm in diameter and nearly 5 mm thick. The NGC Oversize Holder can accommodate coins up to 120 mm in diameter and 15 mm thick. Coins are placed in pre-molded cores that are semi-rigid which are then encapsulated in a clear outer shell. The museum holders are not permanently sealed to allow access to museum staff and researchers.
The more than 100 world coins represent all six inhabited continents and nearly 500 years of history. The group boasts a number of priceless rarities, including a Poland 1621 Gold 100 Ducat that weighs nearly one troy pound and is one of just a few examples known. This incredible rarity was encapsulated in the NGC Oversize Holder designed for large-format coins and medals.
A number of other important gold pieces in the Smithsonian collection were encapsulated by NGC. An Australia 1857 Proof Gold Sovereign is one of only three examples known, while a Mexico 1916 Oaxaca Gold 60 Pesos is one of a handful of survivors from an original mintage of 21 pieces.
Several Asian rarities were also among the highlights. A Korea 1906 Gold 20 Won is one of only a few known examples of this issue, struck in a Japanese style shortly before Korea was officially annexed by Japan. A rare pattern China 1906 Gold Tael, minted for a proposed gold coinage, is another significant rarity.
A Russia 1840 Platinum 12 Rubles is the rarest issue in this short-lived odd-denomination series. Unique or nearly so, it is one of the highlights of the Smithsonian collection.
Traditionally, coins in museum collections are stored in open trays. However, they may be dropped or damaged when they are examined and handled. The exposed coins also may collect dust, fingerprints and other contaminants. Placing the coins in these protective holders allows researchers to view and handle them safely.
Before the 2008 pilot project, the Smithsonian conducted rigorous materials analysis and testing to establish the long-term safety of all of the components used in the manufacture of the holders. Results indicate that the holders will remain inert and stable for decades into the future.
Numismatic Guaranty Corporation grades and authenticates rare coins, tokens and medals. An affiliated company, Numismatic Conservation Services, is the sole professional service dedicated only to the conservation of numismatic objects. NGC and NCS are independent members of the Certified Collectibles Group, headquartered in Sarasota, Fla.
The museum’s National Numismatic Collection consists of more than 1.5 million objects, including coins, medals and paper currency, and preserves the role of money in economic history. Through collections, research and public outreach, the museum explores the richness and complexity of American history. For more information, visit https://americanhistory.si.edu. The museum is located at 14th Street and Constitution Avenue N.W., and is open daily from 10 a.m. to 5:30 p.m. (closed Dec. 25). Admission is free. For Smithsonian information, the public may call