* Renard Diamant: This is the most literal translation, using the standard words for "fox" and "diamond."
* Renard de Diamant: This translates as "Diamond Fox," but emphasizes the fox's association with diamonds.
* Le Renard Diamant: This is the definite article version of the first option, adding a bit of formality.
* Le Renard à Diamant: This translates to "The Diamond Fox," using the "à" preposition to connect the diamond with the fox, implying a possession or connection.
Ultimately, the best choice will depend on the specific context and the desired tone.