Noctilucous Jade can be founded in caves,
You can get about 7 Noctilucous Jades here. See the photo below to find the way to the cave.
You can get about 20 Noctilucous Jade by visiting these spots.
Weapons & Artifacts System
Mondstadt Region Puzzles, Secrets, and Hidden Chests
Original Resin Uses & Condensed Resin
Top Mining Spots