Summon Materia

Alexander - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 25000 - Use x2 per battle
Level 3 - 65000 - Use x3 per battle
Level 4 - 100000 - Use x4 per battle
Level 5 - 150000 - Use x5 per battle

Found - Defeat Snow at Cave in Great Glacier after touching the hot springs.
MP Cost - 120
Attack Power - 120 (Judgment)
Status - Magic +1, Magic def +1, MaxHP -5%, MaxMP +5%
Notes - Inflicts Holy damage.

Bahamut - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 20000 - Use x2 per battle
Level 3 - 50000 - Use x3 per battle
Level 4 - 80000 - Use x4 per battle
Level 5 - 120000 - Use x5 per battle

Found - Defeat Red Dragon in Temple of Ancients.
MP Cost - 100 (Mega Flare)
Attack Power - 65
Status - Magic +1, Magic def +1, MaxHP -5%, MaxMP +5%

Bahamut ZERO - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 35000 - Use x2 per battle
Level 3 - 120000 - Use x3 per battle
Level 4 - 150000 - Use x4 per battle
Level 5 - 250000 - Use x5 per battle

Found - Bring four Huge Materia to Bugenhagen's observatory at Cosmo Canyon, then touch the Blue Huge Materia.
MP Cost - 180
Attack Power - 120 (Tera Flare)
Notes - Magic +4, Magic def +4, MaxHP -10%, MaxMP +15%

Choco/Mog - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 2000 - Use x2 per battle
Level 3 - 14000 - Use x3 per battle
Level 4 - 25000 - Use x4 per battle
Level 5 - 35000 - Use x5 per battle

Found - Talk to the chocobo at the Chocobo Farm
MP Cost - 14
Attack Power - 16 (DeathBlow!!) - 20 (Fat-Chocobo)
Status - Magic +1, MaxHP -2%, MaxMP +2%
Notes - Inflicts Wind damage, sometimes causes Stop.

Hades - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 35000 - Use x2 per battle
Level 3 - 120000 - Use x3 per battle
Level 4 - 150000 - Use x4 per battle
Level 5 - 250000 - Use x5 per battle
Found - Gelnika
MP Cost - 150
Attack Power - 90 (Black Cauldron)
Status - Magic +4, Magic def +4, MaxHP -10%, MaxMP +15%
Notes - Damages opponents and causes the Poison, Confusion, Sleep, Silence, Mini, Frog, Slow, and Paralysis ailments.

Ifrit - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 5000 - Use x2 per battle
Level 3 - 20000 - Use x3 per battle
Level 4 - 35000 - Use x4 per battle
Level 5 - 60000 - Use x5 per battle

Found - Defeat Jenova*BIRTH in Cargo Ship.
MP Cost - 34
Attack Power - 27 (Hellfire)
Status - Magic +1, MaxHP -2%, MaxMP +2%
Notes - Inflicts Fire damage.

Kjata - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 22000 - Use x2 per battle
Level 3 - 60000 - Use x3 per battle
Level 4 - 90000 - Use x4 per battle
Level 5 - 140000 - Use x5 per battle

Found - Sleeping Forest
MP Cost - 110
Attack Power - 100 (Tetra-Disaster)
Status - Magic +1, Magic def +1, MaxHP -5%, MaxMP +5%
Notes - Inflicts Fire, Ice, and Lightning damage. The name was mistranslated and should be "Tri-Disaster."

Knights of Round - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 50000 - Use x2 per battle
Level 3 - 200000 - Use x3 per battle
Level 4 - 300000 - Use x4 per battle
Level 5 - 500000 - Use x5 per battle

Found - Fly a Gold Chocobo to isle on northeast area of continent (though it can't be seen on the map).
MP Cost - 250
Attack Power - 80x13 (Ultimate End)
Notes - Magic +8, Magic def +8, MaxHP -10%, MaxMP +20%

Leviathan - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 18000 - Use x2 per battle
Level 3 - 38000 - Use x3 per battle
Level 4 - 70000 - Use x4 per battle
Level 5 - 100000 - Use x5 per battle
Found - Defeat Godo in Wutai.
MP Cost - 78
Attack Power - 75 (Tidal Wave)
Status - Magic +1, Magic def +1, MaxHP -5%, MaxMP +5%
Notes - Inflicts Water damage.

Phoenix - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 28000 - Use x2 per battle
Level 3 - 70000 - Use x3 per battle
Level 4 - 120000 - Use x4 per battle
Level 5 - 180000 - Use x5 per battle
Found - After Huge Materia Quest at Fort Condor (Disc 2).
MP Cost - 180
Attack Power - 60 (Phoenix Flame)
Status - Magic +2, Magic def +2, MaxHP -10%, MaxMP +10%
Notes - Inflicts Fire damage and casts Life 2 on all characters.

Neo Bahamut - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 30000 - Use x2 per battle
Level 3 - 80000 - Use x3 per battle
Level 4 - 140000 - Use x4 per battle
Level 5 - 200000 - Use x5 per battle

Found - Tornado Maze
MP Cost - 140
Attack Power - 80 (Giga Flare)
Status - Magic +2, Magic def +2, MaxHP -10%, MaxMP +10%

Odin - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 16000 - Use x2 per battle
Level 3 - 32000 - Use x3 per battle
Level 4 - 65000 - Use x4 per battle
Level 5 - 90000 - Use x5 per battle

Found - Defeat Lost Number in Shinra Mansion.
MP Cost - 80
Attack Power - Death (Steel-Bladed Sword) - 75 (Gunge Lance)
Status - Magic +1, Magic def +1, MaxHP -5%, MaxMP +5%
Notes - Instantly kills all opponents. If fighting enemies that cannot be killed, Odin throws the Gunginir spear instead.

Ramuh - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 10000 - Use x2 per battle
Level 3 - 25000 - Use x3 per battle
Level 4 - 50000 - Use x4 per battle
Level 5 - 70000 - Use x5 per battle
Found - Jockey's Room in Gold Saucer
MP Cost - 40
Attack Power - 30 (Judgment Bolt)
Status - Magic +1, MaxHP -2%, MaxMP +2%
Notes - Inflicts Lightning damage. If you miss picking up this materia, you can never get it again.

Shiva - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 4000 - Use x2 per battle
Level 3 - 15000 - Use x3 per battle
Level 4 - 30000 - Use x4 per battle
Level 5 - 50000 - Use x5 per battle

Found - Defeat Bottomswell in Junon.
MP Cost - 32
Attack Power - 24 (Diamond Dust)
Status - Magic +1, MaxHP -2%, MaxMP +2%
Notes - Inflicts Ice damage.

Titan - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 15000 - Use x2 per battle
Level 3 - 30000 - Use x3 per battle
Level 4 - 60000 - Use x4 per battle
Level 5 - 80000 - Use x5 per battle

Found - Meltdown Reactor
MP Cost - 46
Attack Power - 33 (Anger of the Land)
Status - Magic +1, MaxHP -2%, MaxMP +2%
Notes - Inflicts Earth damage.

Typhoon - Sells for 1 gil

Level 1 - 0 - Use x1 per battle
Level 2 - 35000 - Use x2 per battle
Level 3 - 120000 - Use x3 per battle
Level 4 - 150000 - Use x4 per battle
Level 5 - 250000 - Use x5 per battle

Found - Ancient Forest
MP Cost - 160
Attack Power - 110 (Disintegration)
Status - Magic +4, Magic def +4, MaxHP -10%, MaxMP +15%
Notes - Inflicts Fire, Ice, Lightning and Earth damage.

Master Summon - Sells for 1 gil

Enables all Summon materia spells.
Found - Give the Earth Harp to the traveller in Kalm Town (Disc 2 or 3 only). Or, bring the Huge Red materia to Cosmo Canyon. Then master all Summon materia and touch the Huge Materia by going to Bugenhagen's observatory.