Sorry about being obscure. I incorrectly assumed this was a search engine. The question is, in the way that 24h in a d = 24 Hours in a Day, does anyone know the logical answer to "5 C in a G".
The answer could be 5 carats in a gram, in connection with the weight of diamonds. A carat is generally reckoned to be 200 milligrams; though strictly speaking it is 205 milligrams.