The spelling of /d/ is <d> or <dd>. The /ʒ/ sound is spelled <ge> or <zu>.
The contrast is between a stop and a fricative, both voiced and fairly close in the mouth. It might be a slight problem for speakers of languages which do not have the /ʒ/ sound, such as German and Arabic.
The consonant /d/ can occur in any position in the syllable, but /ʒ/ only occurs finally or intervocalically, other than in foreign names or loan words such as gendarme. /ʒ/ is in any case a very rare phoneme, found in only 334 words in the source dictionary.
adder azure adders azures bayed beige brewed Bruges brood Bruges cedar seizure cedars seizures rood rouge rude rouge