NGC Slabs National Collection's Rarities
By Numismatic News
investors were the first adaptors when it came
to the introduction of slabs in 1986. Now, the
scholarly community has joined.
Some 200 rarities in the National Numismatic
Collection at the Smithsonian's National Museum
of American History were placed in customized
plastic holders donated by Numismatic Guaranty
The Smithsonian took this step because the coins
are the most frequently handled.
"We are pleased to be able to provide superb
protection for these rare objects while at the
same time extending access to the research
community," said Brent D. Glass, museum
Glass said the project is a collaboration
between the museum, Numismatic Guaranty
Corporation and Numismatic Conservation
Services, which donated their services and
developed the holders to meet museum
specifications. NGC also provided the materials
necessary to re-house the coins, along with two
storage cabinets which will offer enhanced
security for these numismatic treasures. "NGC is
privileged to work with the museum," said Mark
Salzberg, chairman of NGC.
David J. Camire, president of NCS, added "The
focus that the museum has put on the long-term
preservation of the NNC should be strongly
commended. It's a great privilege to commit our
resources and energy to this important
The 200 holders are made of inert mold-injected
resin and the label, identifying the coin in it,
is printed on acid-free paper. The holder's
overall size is roughly 60 mm wide by 85 mm
tall. It can accommodate coins up to 45 mm in
diameter and nearly 5 mm thick. Coins are placed
in pre-molded cores that are semi-rigid and then
encapsulated in a clear outer shell.
Traditionally, coins in museum collections are
stored in open trays.
Prior to the re-housing effort, the Smithsonian
said it 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
Because of the emphasis on the long-term
preservation of the collection, the pilot
project also will include regular inspections of
the re-housed coins by the curatorial staff.
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.
The museum is closed for major renovations and
will reopen in fall 2008. For information about
the museum, please visit http://americanhistory.si.edu.