999 is pure gold also known as gold bar .. no mix ... u can bought at physical gold bar at maybank (kijang emas) ,poh kong (bunga raya) or u can invest into bank like public bank, maybank which no physical gold involved just by book.

916 is mixed with others .. this is used to make jeweleries .. like gelang and cincin , for future 999 is the correct investment .. u dont keep 916 for investment as it already mixed