Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Gonti's Aether Heart

Whenever Gonti's Aether Heart or another artifact you control enters, you get {E}{E} (two energy counters).
Pay eight {E}, Exile Gonti's Aether Heart: Take an extra turn after this one.

Memnite

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Fountain of Youth

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Galazeth Prismari

Flying
When Galazeth Prismari enters, create a Treasure token.
Artifacts you control have "{T}: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell."

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Ornithopter

Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Darksteel Citadel

Spellbook

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.