Sol Ring

Iron Myr

Golgari Locket

{T}: Add {B} or {G}.
{B/G}{B/G}{B/G}{B/G}, {T}, Sacrifice this artifact: Draw two cards.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Izzet Keyrune

{T}: Add {U} or {R}.
{U}{R}: Until end of turn, this artifact becomes a 2/1 blue and red Elemental artifact creature.
Whenever this artifact deals combat damage to a player, you may draw a card. If you do, discard a card.

Boros Signet

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Orzhov Cluestone

{T}: Add {W} or {B}.
{W}{B}, {T}, Sacrifice this artifact: Draw a card.

Kodama's Reach

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Azorius Signet

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Orzhov Locket

{T}: Add {W} or {B}.
{W/B}{W/B}{W/B}{W/B}, {T}, Sacrifice this artifact: Draw two cards.

Springleaf Parade

When this enchantment enters, create X 1/1 colorless Shapeshifter creature tokens with changeling. (They're every creature type.)
Creature tokens you control have "{T}: Add one mana of any color."

Toxicrene

Reach, deathtouch
Hypertoxic Miasma — All lands have "{T}: Add one mana of any color" and lose all other abilities.

Talisman of Unity

{T}: Add {C}.
{T}: Add {G} or {W}. This artifact deals 1 damage to you.

Marble Diamond

This artifact enters tapped.
{T}: Add {W}.

Trace of Abundance

Enchant land
Enchanted land has shroud. (It can't be the target of spells or abilities.)
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice this artifact: Draw a card.

Dimir Signet

Orzhov Signet

Vulshok Factory

{T}: Add {R}. Put a charge counter on this artifact.
{2}{R}, {T}, Sacrifice this artifact: Create an X/X colorless Golem artifact creature token with haste, where X is the number of charge counters on Vulshok Factory. Activate only as a sorcery.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Savai Crystal

{T}: Add {R}, {W}, or {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Golgari Signet

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Faeburrow Elder

Vigilance
This creature gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Ojutai Monument

{T}: Add {W} or {U}.
{4}{W}{U}: This artifact becomes a 4/4 white and blue Dragon artifact creature with flying until end of turn.

Armillary Sphere

{2}, {T}, Sacrifice this artifact: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.