Obsidian Key黒曜石の鍵

A sharp key cast in obsidian. There should be a lock somewhere that it fits into.
In-game description

What you get from salvaging Obsidian Key (Salvage and Repair Station)

Obsidian Key can be salvaged. Salvaging it gives the following items.

For each material, the amount is "amount used to craft × 0.49 (lower when durability is down, 0.3 at 0 durability) × the item's multiplier", and a fraction is the chance of one more (2.4 means 2, with a 40% chance of 3). The range is from 0 durability to full durability (items without durability always count as full). Scrap parts are a fixed number set by the item level. All items that can be salvaged are listed in salvaging.

How to get Obsidian Key

Placed in or on the Blue Glass Pedestal found inside a scene (building, ruin, camp and so on) (guaranteed)Where: Wilderness Conveyor Puzzle [Azeos' Wilderness] (0–1 per world)
Placed in or on the Blue Glass Pedestal found inside a scene (building, ruin, camp and so on) (guaranteed)Where: Excavation Gauntlet [Breaker's Reach] (1 per world)
Dig up the Digging Spot Sea found inside a scene (building, ruin, camp and so on) (guaranteed)Where: Sunken Sea Cove Puzzle [The Sunken Sea] (0–1 per world)

Scene containers, dungeon placements, guaranteed drops and natural spawns are based on the Obtaining data of the Core Keeper Wiki (Fandom) (CC BY-SA 3.0), because these are not in the game files this site reads. Scene names are the wiki's English names.