13c67163_king___White_Metals_and_Alloys__Reaction_on_Streak
[Possible Alloy] 1. platinum 2. platinum alloy 3. white gold alloy with more than AU 500 4. base alloy [Further evidence] platinum test [Reaction on Streak] 
No attack, the streak is unchanged.
[Ganoksin] Jewelry Making - White Metals and Alloys
Reaction on Streak