Artifacts or Relics are items found in the Abyss by Delvers during their expeditions. While low class Artifacts have little to no use, the higher the grade the more extraordinary its effects are. Regardless of grade, all Artifacts have a pattern that is theorized by Nanachi to imply how many times they can be used before they become dysfunctional.
They are believed to be leftovers from an ancient civilization, and their functioning can't be comprehended by modern technology, let alone imitated.
The Red Whistle Delvers at Belchero Orphanage often go into the 1st layer to search for Artifacts. Though what is found is usually of a lower grade, they can still be sold overseas for decent money. The money from these Artifacts benefits the orphanage.
The most valuable class of Artifacts that can be found. These are items that can change the world and disrupt the balance of power between nations. Retrieving a single one to the surface can guarantee a prosperous future for a whole city or vastly increase the military potential of a country, depending on its use. According to Jiruo, a Special Grade Artifact's value is so great that it can't be measured. Because these Artifacts are so valuable, they are the only kind that White Whistle Delver are not allowed to keep for their own personal use.
The second most valuable class of Artifact that can be found. These are items that are extremely rare or versatile.
Second Grade Artifacts are very rare and usually have very specialized abilities.
Fourth Grade Artifacts are common Relics, usually found on the upper layers.
These Artifacts have never been categorized, thus leaving their Grade open for speculation.