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.
Puzzles, Secrets, and Hidden Chests in Liyue
Puzzles, Secrets, and Hidden Chests in Dragonspine
Confront Stormterror Boss (Dvalin) Guide
Mondstadt Region Puzzles, Secrets, and Hidden Chests
And This Treasure Goes To... Quest Guide
How to Farm Weapon Ascension Materials
Lyney & Lynette