The black stones are artifacts scattered throughout the world of Vyn. They contain an immense amount of energy, and have the ability to posses life forms and grant them great power. Their main purpose is to provide the energy needed to power The Beacon. As they are needed to activate The Beacon, they presumably came into existence at the same time as The Beacon, and The Cycle. During the latest cycle, they appeared during a time known as the Golden Era. Many nobles fought to posses the stones, however, once it was discovered that the possessor of them turned mad, they were no longer desired. The Prophet encountered six of the stones during their travels.
At some point, a stone is acquired by the noble house Dal'Varek. Adila Dal'Varek found the stone before the Dal'Varek Estate was burned down. Her possession of it made her a very powerful mage and warrior, but corrupted her mind. She used her newfound powers to avenge her father's death, by bring "justice" to those who had thus far escaped it; becoming known as "The Bone Judge". For example, Captain Yaanul Oorai was a human trafficker. Adila punished him by crucifying him above a bath of acid.
The Prophet would later work with Jespar Dal'Varek in order to find his sister. Jespar did not believe that his sister possessed the stone, but when he confronted her, he discovered that she did have the stone, and the effects it had on her. After Adila killed Jespar, The Prophet confronted her, and killed her. The Prophet took the stone and gave it to Lexil Merrâyil, who used it to power The Beacon.
Jiro Dal'Geyss bought a black stone from a pedlar from Qyra. It stayed within the family until Ketaron Dal'Geyss had a son, Rynéus. Rynéus was born crippled, leading to Ketaron abandoning him. His wife, angry at his decision, stole an object from the Dal'Geyss Vault, and gave it to Rynéus before he was sent away. This object was the black stone.
Rynéus later ends up in a town known as Silvergrove, where he is adopted by a man. The villagers were fearful of him due to his deformities, leading to him living a lonely life. One night, an old woman died in front of Rynéus' house. The villagers believed Rynéus killed her with wild magic. This led to them storming his house, and killing Rynéus' father. Rynéus, fearful of the world he was in, created a new one with the power of the black stone. In this world, everything that Rynéus wished would happen, happened. However, everyone in this world was not really there, as the world was not real. Their real bodies were in the real Silvergrove, and due to them not being in control of them, they were unable to eat, thus dying in the real world. Rynéus at first loved this new world, but eventually grew tired of everyone doing as he wished. He was, in effect, in a world populated solely by himself.
The Prophet, having learned about Rynéus from Dal'Geyss, went to Silvergrove. They entered Rynéus' world, but did not have to do everything the Rynéus wished. To acquire the black stone, Rynéus asked that they grant him three wishes. They were able to fulfil the first two wishes, but for the third wish, Rynéus asked that The Prophet stayed with him. The Prophet does not agree, and Rynéus reveals the true nature of Silvergrove to them. Eventually, Rynéus agrees to give The Prophet the stone, but before he could, the stone turns him into an incarnation of it; a very strong Oobâya.
The Prophet defeated this incarnation, and the fake world was destroyed. In the real Silvergrove, The Prophet discovers the decaying corpses of its inhabitants, and sees Rynéus' true form. Rynéus dies, and The Prophet takes the black stone. They gave the stone to Lexil Merrâyil, who used it to power The Beacon.
The League for the Apothecarii was once in possession of a black stone, however it is claimed by them that it was lost. Samuel Dal'Galar was a healer who worked for the apothecarii, but his methods diverged from those of the League. Because of these, he was barred from Ark. However, he had taken the stone with him. It is believed he was using it to create something known as "The Angel," which could heal anything.
In reality, The Angel project, was Dal'Galar's efforts to resurrect his daughter. Dal'Galar's daughter, Maya, had died, and he had preserved her corpse in hopes of resurrecting her, turning her into an "Angel" that would be able to help people more than he could. Dal'Galar was using the power of the stone to resurrect his daughter. He succeeded in this endeavor, but his success was short lived. After Maya is resurrected, her skin turned black and she said that something is burning her from the inside. A blast of energy was released killing Dal'Galar and rendering Maya unconscious. The Veiled Woman appeared to the unconscious Maya, revealing her fate: she is later to be known as Calia. After this, the stone remained in Dal'Galar's castle, until it is later found by The Prophet and a now adult Calia. The Prophet took the stone, and gave it to Lexil Merrâyil, who used it to power The Beacon.
During their cycle, the Pyreans collected three black stones. These black stones were used as the power source of their Beacon, and when it was activated without the Numinous, The Cleansing occurred. These stones were later found when The Prophet, Tealor Arantheal, Yuslan Sha'Rim, and The Prophet's companion found The City of A Thousand Floods. The Prophet was able to use the stones to incite the echo, as they were connected to the cleansing of the Pyreans. It is unknown how the Pyreans acquired these stones.