I'm looking for a Disney comic, in which the characters (pretty sure it's about Uncle $crooge and his nephews, but it could also be Mickey Mouse), go after an Iceberg which becomes green when the sunlight go through it. Those who found it think it must contain a gigantic emerald, and everyone starts looking for it.
At the end of the story, other icebergs of other colors are found, and there are no gemstones in them, but enormous round bottles of exquisite syrups, which a ship had to throw in the ocean to avoid sinking.
I read it about 15-20 years ago, in French.
Does anyone know the title of this comic?