A specific quest for Invoices needs Noctilucous Jades as a trade. This guide on Where To Find Noctilucous Jade In Genshin Impact will tell you exactly where to find this rare and valuable material, that may also be used in Ascending characters and weapons later in the game.
I spent several hours exploring the world before finding some Noctilucous Jade, so it’s quite rare, especially in the earlier areas. I’m sure there are other places you can visit to mine some but for the quest you only need a couple so this location should be perfect for you to mine some Noctilucous Jade so you can complete the quest.
Where To Find Noctilucous Jade In Genshin Impact
It’s to the West, near Qiongji Estuary. That’s East of Wangshu Inn which is a long distance South West of Mondstadt. There is a road leading through the area, you will find the blue, gem-like stones directly next to the road. They can take a bit of a beating, using the Earth element can help destroy the rocks much faster. There are likely many other locations to find Noctilucous Jade mining spots but this is enough for you to finish the quest where you need to trade the Jade for the invoice.
If the Jade becomes a valuable material later in the game, I’ll revisit the guide and see if we can find some more locations.