You have to decide which drum you're going to beat: sex or death.
Left radical is 'metal' (金), right is a Non-General Use character meaning
'stop'. It was originally a pictograph of an eye on twisted legs, and indicated
someone stopping and staring. It is used here phonetically to express 'white'. Henshall
suggests as a mnemonic: 'Stop and stare at silvery metal.'
There is a conflict between Henshall and the JWP kanji word processor over this character and its combinations. JWP seems to be saying that 'shirogane' can only be 白金, not this character. It also seems to say that 銀漢 is pronounced 'ginkan', not 'ginga', as Henshall says. I don't know who's right here.