The award for the most subtle use of sun rays on a US commemorative coin has to go to the 1926 American Independence Sesquicentennial gold $2.50 coin (Quarter Eagle) designed/sculpted by John Ray Sinnock, eighth Chief Engraver of the US Mint.
The coin was issued in conjunction with the 150th anniversary of the signing of the
Declaration of Independence and American independence, in general. A same-themed silver half dollar was also struck; both coins were sponsored by the Sesquicentennial Exhibition Association (the organizers of the Sesquicentennial International Exhibition in Philadelphia, PA).
On the coin's reverse, sun rays emanate from behind the bell/clock tower of the Pennsylvania State House - more commonly referred to as Independence Hall. The sun's rays were sculpted in such low relief, however, that they are difficult to see on a well-struck coin, and almost impossible to see on a weakly-struck example.
A potential issue arises with the coin's design when geography is brought into the equation. The coin shows the South elevation of Independence Hall (the viewer is looking north). If I recall correctly, the sun rises in the east and sets in the west. I'm not sure what time of day (and/or what time of the year) the sun would be directly behind the north side of the building, and low enough in the sky, such that its rays would be equally distributed on either side of the tower in the view depicted. So, I'll have to leave that to someone much more knowledgeable in the field of geography and/or solar positioning.
1926 American Independence Sesquicentennial, Gold Quarter Eagle

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