Unstable Obelisk

{T}: Add {C}.
{7}, {T}, Sacrifice Unstable Obelisk: Destroy target permanent.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Thran Dynamo

Sol Ring

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Stonespeaker Crystal

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Stonespeaker Crystal: Exile any number of target players' graveyards. Draw a card.

Forsaken Monument

Colorless creatures you control get +2/+2.
Whenever you tap a permanent for {C}, add an additional {C}.
Whenever you cast a colorless spell, you gain 2 life.