Sourcestone Unknown.

Tier UT
On Equip +110 HP, +110 MP, +6 SPD
XP Bonus 7%
Soulbound Soulbound
Feed Power 1,000
Forging Cost 60 Legendary Material / 160 Rare Material / 180 Common Material / 1560 Forgefire / 2 Mark of the Void Entity / 2 Lost Halls UTs/Cultist Hideout UTs/The Void UTs UT(s)
Dismantling Value 15 Legendary Material / 40 Rare Material / 45 Common Material

Loot Bag Assigned to White Bag
Drops From Void Entity
Voided Epic Quest Chest

Blueprint Sourcestone Blueprint
Drops From Void Entity
Obtained Through The Tinkerer (50x Ancient Schematic)

Please note “Unknown.” is the actual description of the item in-game.

The Sourcestone is a fairly decent ring, with good HP and MP bonuses. The lack of any offensive stats make it more suitable to ability-reliant classes, such as Priest and Knight. Rushers can take advantage of both the MP and Speed bonuses.

Unless you are playing a Priest or Necromancer, most players looking for defense will prefer a standard HP ring. Players looking for offense may prefer the Divine Coronation or the coveted Omnipotence Ring. If you don’t care about having any HP boost, the Twilight Gemstone allows you to cast abilities at a 30% discount, in addition to its +110 MP and +6 WIS.

Wearing this ring with the rest of the Void Archer set enitrely negates the SPD penalties from the armor and quiver, and even gives a net increase of +1 SPD.

Before Lost Halls 2.0, the ring gave +80 HP, +80 MP, and +4 SPD.

Before Patch X.26.0.0 (May 2018) the Sourcestone had the following sprite:
Sourcestone (old)

Untiered Rings
SourcestoneUT. Sourcestone
Set Tiered Rings