Pay {7} twice, create 2 copies of Powerstone Shard, leaving {3}.
Tap 2 of the token Powerstone Shards for {6}.
Pay {7}, leaving {2}, to create another token copy of Powerstone Shard.
Tap the 2 remaining untapped Powerstone Shards for {8}.
Pay {7} to create a token copy of Powerstone Shard, tapping it for {5}, leaving you with {8}.
Pay {7} to create a token copy of Powerstone Shard, tapping it for {6}, leaving you with {7}.
Pay {7} to create a token copy of Powerstone Shard, tapping it for {7}, leaving you with {7}.
At This point, each Powerstone Shard will tap for more mana than it costs, allowing you to generate infinite {C}.
Pay infinite {C} to create infinite copies of Cogwork Assembler.

Infinite colorless mana

Infinite creature tokens with haste

Infinite ETB

Cogwork Assembler

Powerstone Shard

Activate Urza by paying {6}, creating a token copy of Powerstone Shard that is a 1/1 Soldier in addition to its other types.
Activate the Powerstone Shard token by tapping it, adding {C} for each Powerstone Shard you control.
Repeat two additional times.
Activate the original Powerstone Shard by tapping it, adding {C} for each Powerstone Shard you control.
Repeat steps 1 through 3.

Infinite creature copies of artifacts you control

Infinite creature tokens

Urza, Prince of Kroog

Thousand-Year Elixir

Akroma's Memorial

Activate Chrome Dome by paying {5}, creating a token copy of Powerstone Shard.
Activate a Powerstone Shard by tapping it, adding {C} for each Powerstone Shard you control.
Activate Chrome Dome by paying {5}, creating a token copy of Powerstone Shard.
Activate two Powerstone Shards by tapping them, adding {C}{C} for each Powerstone Shard you control.
Repeat steps 1 and 2 infinitely.

Combos with "Powerstone Shard"