I found this term in DEX and wiki entry. It's possible to say "radianta" as well, which refers more to sun's warmth, it seems to me. "Radiata" is more common in Romanian, me thinks.

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Note added at 4 hrs (2016-09-05 17:35:10 GMT)
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sorry, i forgot to add this link: https://en.wikipedia.org/wiki/Radiant_crown. It shows the coin with a radiant crown. So I would call this solution "monede cu coroana radiata"