Dark Sphere

A strange dark sphere was given to Szeth by Gavilar upon his death, who said "Take this. They must not get it." 
Szeth later hid the sphere in Jah Keved.
==Appearance==
The sphere given to Eshonai is described as having a dark yet faintly violet glow that she seemed to believe is Voidlight.
The sphere given to Szeth is described as small, crystalline, and completely dark. It glows with a black light as if it has an aura of blackness, a phantom light that is not light. Faintly violet. It seems to suck in the light around it.
The sphere (i.e., the Honor's Drop ruby) with which Dalinar traps the Unmade Nergaoul glows with a dark, bizarre light.
(According to Brandon, the dark light of the sphere is something different and distinct, and is related to a Shard.Book signing, Seattle, WA, 10/14/13)*
==History==
Gavilar had possessed several unusual black spheres, having had access to an unknown number of them.JordanCon 2018, 4/20/18JordanCon 2018, 4/21/18
Gavilar gave a sphere to Eshonai on the day of his assassination and told her to give it to the Council of Five after a conversation about parshmen and Parshendi.
Later that same day, Gavilar gave Szeth a similar sphere at the end of their fatal duel. Gavilar told Szeth that he must take that sphere so that "they" do not get hold of it. (It remains unclear as to just who "they" are.)
Szeth then hid the sphere in Jah Keved.
Later still, Szeth gave the sphere to Navani. She assigned her scientists to do experiments with it, but it exploded, killing them. Navani suspects that the sphere contained Anti-Voidlight, and Gavilar planned to use it to kill Odium.
Brandon has since confirmed that both of these spheres contained the same thing.Book signing, Orem, UT, 9/19/18
==Relevance==
It is said that this sphere is used to trap spren.Oathbringer, Prologue
==Present Day==
Dalinar traps the Unmade Nergaoul in the King's Drop ruby at the Battle of Thaylen Field. Navani says it reminds her of a sphere that Gavilar had. (She does not appear to be aware that there was more than one sphere.) Further, she believes that Gavilar "made" the sphere she saw.
==Notes==
Took claimed to have stolen a similarly described sphere from the Nightwatcher.
Before giving Eshonai a sphere, Gavilar tells her that slaveform came about after an "ancient, crucial spren" was captured.
In Urithiru's library drawers, there exists reference to the Bondsmith Melishi planning to capture an Unmade, to deny the use of Voidlight and Forms of Power. A "strike team" (presumably of Knights Radiant in support of Melishi) was subsequently sent to imprison Ba-Ado-Mishram, whom the Radiants believed to be the source of Voidlight.
Brandon hasn't explicitly confirmed what the black spheres contain. He has said that the sphere's light is different from Stormlight, related to Odium, and that "it is what the third book (i.e., Oathbringer) implies it is."JordanCon, 4/21/18
*According to a reader, this is actually anti-Voidlight.Discussion, /r/Cosmere, 11/3/23
==Speculation==
Its Investiture is of Odium, like Stormlight is of Honor, by which Voidbinding is fueled. The light of the sphere can be referred to as Voidlight.Book signing, Seattle, WA, 10/14/13
Could this be the spren of which Gavilar spoke (i.e., " ... an ancient, crucial spren ... ") which inhabits the sphere of which Eshonai and members of the Council of Five are so afraid, which ultimately is the impetus for Gavilar's assassination?
Based on the fate of Nergaoul in Oathbringer, Ba-Ado-Mishram could also be trapped in a sphere.
With Eshonai's death, just what has happened to the sphere that was in her possession? Does Venli have it, along with Timbre too?
==References==
Category:Gemstones
Category:Magical Objects