Coins - 1990 Proof Set
Certificate of Authenticity and Coin Specifications
For the 1990 proof set, the US Mint introduced the Certificate of Authenticity
in addition to the Coin Specifications on the enclosed purple card.
On one side of the purple card, the US Mint added the Certificate of Authenticity in addition to their seal from
the Department of Treasury. In the earlier purple proof sets, this side of the card only had the Mint's seal
centered on the purple card stock.
The text states:
The United States Mint certifies that these proof versions of current United States circulating coinage were
produced and packaged at the United States Mint, San Francisco, California. Each coin bears the mintmark “S”
designation of that facility.
United States proof coins are produced from carefully selected planchets, or coin blanks, that have been
burnished to a high luster. The polished blanks, which are carefully handled to minimize scratches and
abrasions, are struck on specially adapted coining presses. Each coin is struck at least twice to bring forth
the most minute detail with remarkable clarity.
The surfaces of the coinage dies for striking proof coins are meticulously processed to create a frosted
appearance of the image on the die. The background surface is polished and buffed to a mirror-like finish. The
dies are also buffed during the striking process.
The finished coin with its frosted cameo image on a mirror-like field is carefully inspected—with gloved
hands to protect its surface—before being assembled into sets. The proof coins are then placed into transparent
presentation cases.
Proof coins, referred to as “Master Coins” in the early days of the Mint were originally produced to “prove
the correctness of the dies.” These first pieces, struck with extra care and bearing a high polish, were
reserved for the Mint’s Cabinet of Coins Collection and sometimes used for special presentations. They were
first offered for sale to the public around 1858 and are produced under the authority of Section 5111 (a)(3),
Title 31 of the United States Code.
Proof coins are a supplemental program of the United States Mint, produced at no net cost to the government,
with profits deposited to the General Fund of the Treasury of the United States.
Donna Pope
Director of the United States Mint
The other side of the purple card enclosed with the 1990 proof
set provides a table showing the specifications for each of the five proof coins in the set.
The specifications include:
United States Mint Proof Coin
Set
|
Specifications
|
Denomination
|
Cent
|
Nickel
|
Dime
|
Quarter
|
Half Dollar
|
Obverse
|
Lincoln
|
Jefferson
|
Roosevelt
|
Washington
|
Kennedy
|
Designed by
|
V.D. Brenner
|
Felix Schlag
|
John R. Sinnock
|
John Flanagan
|
Gilroy Roberts
|
Reverse
|
Lincoln Memorial
|
Monticello
|
Torch, Olive Branch, Oak Branch
|
Heraldic Eagle
|
Heraldic Eagle
|
Designed by
|
Frank Gasparro
|
Felix Schlag
|
John R. Sinnock
|
John Flanagan
|
Frank Gasparro
|
Composition
|
Copper Plated Zinc 2.5% Cu Balance Zn
|
Cupro-Nickel
25% Ni Balance Cu
|
Cupro-Nickel Clad 8.33% Ni Balance Cu
|
Cupro-Nickel Clad
8.33% Ni Balance Cu
|
Cupro-Nickel Clad 8.33% Ni Balance Cu
|
Standard Weight
|
2.500 g
|
5.000 g
|
2.268 g
|
5.670 g
|
11.340 g
|
Standard Diameter
|
0.750 in 19.05 mm
|
0.835 in 21.21 mm
|
0.705 in 17.91 mm
|
0.955 in 24.26 mm
|
1.205 in 30.61 mm
|
Edge
|
Plain
|
Plain
|
Reeded
|
Reeded
|
Reeded
|
FURTHER INFORMATION: United States Mint,
Washington DC 20220
|
In later sets, the US Mint advises, "To preserve the beauty of your Proof Set, it should be stored in a cool,
dry place."
Click 1990 Proof Set to view the contents of the proof set package.
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