History of Resonant Alloy

Resonant Alloy is an uncommon crafting material introduced in Season 16 with Destiny 2: The Witch Queen, capped at 80. It is spent on weapon crafting to unlock intrinsic and enhanced intrinsic perks; raid weapons use Harmonic Alloy instead.

Acquisition

Dismantling Legendary weapons (occasionally Rares), five from Throne World Engrams after Rank 30 with Fynch, and some quest rewards.