- Although at a much slower rate.

Crystal 4 gear drops from:
- 5-Star Dungeons in Uber-11 Prime and Geode Topside worlds
- Uber-10 and above Delves (115 Depth)

requires:
- 250 Gearcrafting skill
- 15,000 Power Rank
- unlocking and activating Master Crafter III on the Gearcrafter's Terminus

When crafting Crystal 4 recipes which requires 250 Gearcrafting skill.
- Small chance of Crystal 5 from any Gearcrafting recipe
- Small chance for Gearcrafter's Vault from any Gearcrafting recipe.

Requires: 4,000 Power Rank

Chance to be found inside Gearcrafter's Vault.
- Can be found in any Uber-1 or higher dungeon chests.
- Increased chance for Gearcrafter's Vault from world difficulty.
- Uber-9 should guarantee one Gearcrafter's Vault per dungeon.

Thanks to Nik for providing the following information.