This is a 1964 Kennedy half dollar made by Corning Glass Company for AT&T and is made of clear photochromic glass. This was made as a possible replacement to silver.
The following is from StacksBowers 4/16 sale.
Not listed in Judd or any other pattern reference prior to 1994. The image of President Kennedy and the other design elements are translucent white in color, and are photographically developed within the coin disk or "planchet," not applied to the outer surfaces as might be imagined from looking at the illustrations. The coin disk itself is composed of clear, colorless, photochromic glass, the characteristics of which will be discussed below.
Back in 1964, before the adoption of the copper-nickel clad sandwich alloy which is familiar to everyone today, substantial research was carried out to determine what materials might be suitable to replace silver in dimes, quarters and half dollars. The AT&T Company, having large numbers of coin operated telephones nationwide, took a major interest in the project and was responsible for much of the research carried out, including the testing of proposed materials for their electrical and magnetic properties.
At that time Corning Glass Works contacted AT&T indicating that they had considered the development of a glass or ceramic coinage, and arranged for a meeting with AT&T at the latter's Indianapolis laboratory to confer about coinage requirements and to present for consideration sample glass coins. The meeting between representatives of AT&T and Corning occurred on April 30, 1965, and was the subject of a memorandum titled Conference on Glass Coinage dated May 14, 1965. This memorandum is quoted at length by Andrew Pollock in his 1994 reference United States Patterns and Related Issues. A few brief quotes are presented here:
"....as an estimate a 50-cent size [glass] disc would cost about 2 cents. This is comparable to the material cost of base metal discs. The same discs as he exhibited had a very pleasant ring, and extremely hard and clean surface, and were very light....The larger denominational coinage (particularly the 50-cent and $1.00 pieces) appeared most reasonable as glass discs, offering the advantage of reduced weight."
It is obvious from the memorandum that the pattern glass half dollar was produced by Corning Glass Works in order to promote the possibility of expanding their product line into the manufacture of coins, or at least the photo-sensitive glass discs needed to make them. It is also apparent that they were not operating under contract from the Mint or any other government agency to produce these experimental pieces.
A note about photochromic glass: this is an unusual material which is reactive to ultraviolet light. When ultraviolet light is passed through a mask into the glass it creates a crystalline image which can then be developed through a controlled heat treatment process. The glass is then etched chemically to render the image visible.
According to the consignor of the presently offered example, the tradition at Corning was that four examples of the variety were made. At present only two are accounted for with certainty:
1 - The present example. Our consignor notes, ".....many of my family worked for Corning and to the best of my knowledge the coin which I have has been in my family's possession for several decades." -- Editor's note - the coin brought $3,525.
2 - Ex our (Bowers and Merena's) sale of the Brooks Collection, June 1989, lot 2621; later offered for $7,500 by Devonshire in a Numismatic News advertisement dated November 12, 1991. This specimen had been acquired by our Brooks Collection consignor from Corning Glass Works in 1979. It was obtained from a Richard M. Smith, senior market development specialist. Reportedly, it was the only specimen then available from the company.
3 - Undetermined. Possibly in the archives of AT&T, as they reported having received a specimen from Corning according to the May 14, 1965, memorandum cited above.
Photo courtesy of StacksBowers.