Shadowgem

Shadowgem is a mineral.

Source

Miners can extract Shadowgems from Copper and Tin veins, and Jewelcrafters can extract Shadowgems from Copper and Tin ore. Other potential sources include mob drops and chests.

Shadowgem as an ingredient

Shadowgems are used in the following recipes:

Blacksmithing

[Big Black Mace]
Deadly Bronze Poniard
Heavy Bronze Mace
Runed Copper Breastplate

Engineering

Shadow Goggles
[Goblin Jumper Cables]

Jewelcrafting

Bronze Band of Force
Gloom Band
Ring of Twilight Shadows
Thick Bronze Necklace

Leatherworking

Shadowskin Gloves