Remnants of finely crafted items. Used to purchase new items from certain vendors.
The Bright Dust is an Eververse currency in Destiny 2.
Unlike Silver, which is an another Eververse currency, Bright Dust is obtainable by playing the game.
Bright Dust is obtained by completing Vanguard, Crucible and Gambit weekly and bonus bounties. Seasonal Event bounties reward the players with Bright Dust, as well.
A weekly bounty gives 200 and a bonus bounty gives 10.
Engrams with cosmetics may also contain Bright Dust.
Bright Dust is used to buy cosmetic items at Eververse. Only 14 items are available for purchase each week, 2 of them are always the Gleaming Boon of the Vanguard and Gleaming Boon of the Crucible.