THE PRIDE OF A LOVER: Nier Replicant Quest
You can pick up the quest from a man standing just below the lighthouse in Seafront. Initially, he will not assign the task, you have to speak with him few times.
He will ask you to get fluorite from the strange-thing store in Facade, so he can make a fashion accessory for his lover. The man at the store will inform you that their supply has been exhausted, and you need to go back into the Barren Temple to collect Fluorite.
How To Reach Barren Temple & Get Fluorite
You can’t reach the Barren temple directly due to a desert storm on the way. At first, you need to get a royal compass from the masked guard of King’s Manson at Facade.
There is no definite location of fluorite inside the temple, we found it inside the first room on the right. You’ll see the fluorite glowing.