Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Silence

Your opponents can't cast spells this turn.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.