Ruidium

Ruidium is a red mineral that emits the power of Alyxian, the Apotheon. It was discovered underneath Ank'Harel by the Allegiance of Allsight and named by the Consortium of the Vermilion Dream after Ruidus because of its red color. Ruidium can be used in magical items, but prolonged usage of these items can cause physical and emotional corruption, which is potentially fatal.

Description
Ruidium is described as "a slick, oily stone veined with blood-like streaks". The mineral has magical properties that derive from Alyxian, the Apotheon. It exists in ore veins issuing from the planar rift to the Netherdeep.

Prolonged usage of an item containing ruidium can cause physical and emotional corruption. Initially, rashes can develop. Later stages include ruidium veins lacing the body and the growth of crystal protrusions on the body's exterior. Death can result from ruidium corruption. Emotional corruption occurs as the wielder experiences the torment of Alyxian through the common link of the ruidium.

The name "ruidium" derives from the misattribution of the mineral's origin to Ruidus by the Consortium of the Vermilion Dream, a religious group that venerates Ruidus, because of the similarity in color. Despite the term "ruidium" being a misnomer, it became the official term for the mineral in academic vernacular.

History
Ruidium is linked with the struggle between Alyxian and Gruumsh during the Calamity. Gruumsh vowed to obliterate the city of Cael Morrow due to the population's devotion to Corellon. Alyxian interposed himself between Gruumsh's spear and the city, saving it from annihilation. Nevertheless, the energy of the spear transformed the jungle landscape into desert and razed Cael Morrow. At the same time, a rift was torn and "alien energy from an unknown realm" poured into the Material Plane. This energy and the waters of Cael Morrow mingled to create the realm of the Netherdeep. The memories of Alyxian generated ruidium while shaping the Netherdeep. Ruidium deposits exist in the Netherdeep and near the planar rift in the Material Plane to the Netherdeep.

During the 830s PD, academics of the Allegiance of Allsight discovered a "strange mineral in the sunken ruins" of Cael Morrow beneath Ank'Harel and began using magical items containing the mineral. Shortly after its initial discovery, the Consortium of the Vermilion Dream learned of its existence and named it ruidium. The presence of ruidium in Ank'Harel is due to the extraction of a sample by an agent of the Consortium.

If the adventuring party in Critical Role: Call of the Netherdeep successfully relieves Alyxian of his bondage in the Netherdeep, all ruidium ceases to exist.