There is a phrase in Almayer's Folly by Joseph Conrad which seems to me an idiom, but I can't find it is. Here is an excerpt from the story with the phrase in question in bold:
Lingard, a rich merchant, has just asked the main character to marry his daughter, and he is evaluating the prospects of seizing the fortune of Lingard through this marriage.
The consideration, the indolent ease of life - for which he felt himself so well fitted - his ships, his warehouses, his merchandise (old Lingard would not live for ever), and, crowning all, in the far future gleamed above char, where, made king amongst men by old Lingard's money, he would pass the evening of his days in inexpressible splendour.
I think it is clear that 'gleamed above char' is expressing that what follows next in the paragraph is the most precious thing to him about that future, just as the contrast of a flash of bright light over charcoal.
Is this an idiom or did Conrad just make it up?