Difference between "face of" and "faces of" in Hebrew

Question

If you want to say "face of gold" (sing.) in Hebrew, you say פני זהב.

If you want to say "faces of gold" (plural) in Hebrew, you say _______.

Part of the difficulty is that the Hebrew word for "face", פנים, is one of those unique nouns which are plural in their grammatical form, but singular conceptually. That being the case, is there any way to identify between whether a verse means "face of" or "faces of", assuming there weren't other telling signs in the verse?

A few examples:

• In Bamidbar 20:10, when it speaks of פני הסלע, is there any way to know whether it means "face of" or "faces of" the rock?
• In the words (from the Ramban) of הסתר פני הגאולה, is there any way to know whether he means "face" or "faces" of redemption?

Answer 1

If you want to say "faces of gold" (plural) in Hebrew, you also say פני זהב

...or, if you want to refer to particular gold faces made by Betzalel, you could say פני הכרבים.

It seems that there's no difference in the word used in either case.