The Lumina is the newest Exotic weapon added into Destiny 2. This unique hand cannon fires bullets that damages enemies, but heals/buffs fellow Guardians. Unlike any gun in the game, the Lumina is perfect for those seeking to take a more supportive role. Tied to a multi-step quest, you’ll need to kill a lot of enemies if you want to unlock the Lumina. However, unless you obtained the Thorn, starting this quest may seem confusing.
To start the Lumina quest, go tot he EDZ and land in the Trostlands. Now head past the church and enter the large Salt Mines. Fight your way to the room with the collapsed elevator and step onto the Fallen Transporter to the left of the elevator. This will warp you to the top of the mines where several Fallen are patrolling.
Kill these enemies and walk to the very top where am energy barrier is blocking your path. Turn around so you are facing the cliffs and hop over the guard rail. While looking this direction, turn to your right and should see a small, hidden cave entrance at the end of the guard rail. Hop into this entrance and explore the camp. The chest with the quest is in the back left corner by the cliffside. This will give you the first step of the Lumina quest and begin your long journey.