I was searching for "Moonstone Crystals" to add to one of my pet's treasure chests and using the "Account Search" function, a list of all "Moonstone Crystals" appears. In the list is a "Healing Moonstone Crystal", but when you click the link, there is no item found, even though there's an official item ID (137590). Is this something that was created, but never actually made the artwork on site?

Edited to add:

The same is the case for the "Thief Moonstone Crystal" (item ID 137687).

In both cases, there is a "Baguette Crystal" and "Tear Crystal" of both.

Make Battle Crystals In All Shapes

they don't exist as items available for users.