Evolution Items

Metal Coat - Olivine City: trade Krabby for Voltorb (holds the item)

Magnemite and Magneton can hold this item.

            Holding increases attack power of steel-types by 20%.
            Hold and trade in order to evolve Onix / Scyther.

Dragon Scale
Horsea, Seadra, Kingdra, Dratini, Dragonair, Dragonite can hold this item.
            Hold and trade in order to evolve Seadra.

Deep Sea Scale

Clamperl, Chinchou, Lanturn and Relicanth hold this item.
              Hold and trade in order to evolve Clamperl into Gorebyss.

      If Clamperl holds this item, it doubles it´s SpDef.

Deep Sea Tooth

Clamperl, Sharpedo and Carvanha can hold this item.
              Hold and trade in order to evolve Clamperl into Huntail.

      If Clamperl holds this item, it doubles it´s SpAtk.

Electrizer

Elekid and Electabuzz can hold this item.

            Hold and trade in order to evolve Electabuzz.

Magmizer

Magby and Magmar can hold this item.

            Hold and trade in order to evolve Magmar.

Leaf Stone - Celadon/Goldenrod Mart
Exeggcute and Tangela can hold this item.
            Cost: 2.100$

            Evolves certain Pokémon when used on them.

Water Stone - Celadon/Goldenrod Mart

Cost: 2.100$
            Evolves certain Pokémon when used on them.

Fire Stone - Celadon/Goldenrod Mart

Cost: 2.100$
            Evolves certain Pokémon when used on them.

Thunder Stone - Celadon/Goldenrod Mart

Shinx can hold this item.

            Cost: 2.100$
            Evolves certain Pokémon when used on them.

Dusk Stone

Murkrow can hold this item.
            Evolves certain Pokémon when used on them.

Moon Stone

Clefairy can hold this item.
            Evolves certain Pokémon when used on them.

Sun Stone

Drowzee (Berry Forest) can hold this item.

    Can be found by using "Dig" on cracks in caves.

    Evolves certain Pokémon when used on them.

Dawn Stone - Johto Safari Wet Zone from Old Lady

Cost: 20.000$

            Ralts can hold this item.

            Causes male Kirlia to evolve into Gallade.
            Causes female Snorunt to evolve into Froslass.

Shiny Stone - buy from man in Safari Kanto

Cost: 20.000$

            Togepi can hold this item.
            Evolves certain Pokémon when used on them.

Oval Stone

Happiny can hold this item.

      Can be found by using "Dig" on cracks in caves.

      Evolves Happiny into Chansey when used on it.

Protector

Rhydon (Cerulean Cave) can hold this item.
     Evolves Rhydon into Rhyperior when used on it.

Reaper Cloth

Duskull can hold this item.

      Can be obtained in Halloween events.

      Evolves Dusclops into Dusknoir when used on it.

 

King´s Rock

Cost: 15.000$ - Slowpoke Well

              Slowbro, Politoed, Poliwhirl and Poliwag can hold this item.
              Evolves certain Pokémon when used on them.

      Increases the chance of causing a target to flinch by 10%.

Razor Claw

Sneasel and Snorunt can hold this item.
              Evolves Sneasel to Weavile when used on it.

      Holding increases the critical hit ratio by 1.

Razor Fang

Gligar and Murkros (Desert Lagoon) can hold this item.
              Evolves Gligar into Gliscor.

      Holding increases the chance of causing a target to flinch by 10%.

Prism Scale

Feebas can hold this item.
              Can be found by using "Dig" on cracks in caves.

      Evolves Feebas into Milotic.

Up-Grade

Porygon can hold this item.
              Evolves Porygon into Porygon2 when used on it.


Type-Booster

Dragon Fang - Route 6 from NPC
 Bagon, Shelgon or Salamance can hold it, when you catch them.
            Holding increases the power of Dragon-attacks by 20%.

Miracle Seed - Goldenrod Underground Basement in an empty flowerpot /Goldenrod Mart

Cost: 2000$

            Holding increases the power of Grass-attacks by 20%.

Twisted Spoon

Abra and Kadabra can hold this item.

            Holding increases the power of Psychic-attacks by 20%.

Light Clay - Route 9
Holding increases the duration of Reflect/Light Screen from 5 to 8 turns.

Magnet - Route 37
Holding increases the power of Electric-attacks by 20%.

Spell Tag

Misdreavus can hold this item.

            Holding increases the power of Ghost-attacks by 20%.

Never Melt Ice - Island 4, Icefall Cave B1F
Holding increases the power of Ice-attacks by 20%.

Mystic Water - Goldenrod Mart

Golduck (Dragons Den) can hold this item.

            Cost: 2000$

            Holding increases the power of Water-attacks by 20%.

Charcoal - Goldenrod Mart

Slugma, Ponyta and Rapidash can hold this item.

            Cost: 2000$
            Holding increases the power of Fire-attacks by 20%.

Silk Scarf
Holding increases the power of Normal-attacks by 20%.

Sharp Beak
Pidgeotto can hold this item.
            Holding increases the power of Fly-attacks by 20%.

Hard Stone
Geodude and Onix can hold this item.
            Holding increases the power of Rock-attacks by 20%.

Soft Sand
Diglett can hold this item.
            Holding increases the power of Ground-attacks by 20%.

Poison Barb

Tentacruel, Budew can hold this item.

            Holding increases the power of Poison-attacks by 20%.

Black Glasses
Drowzee can hold this item.
            Holding increases the power of Dark-attacks by 20%.


Stat-Booster

Quick claw - Free from Lady with Persian in National Park

Sandshrew and Sandslash can hold this item.

            Holding gives a 20% chance of attacking first.

Black sludge

Grimer and Muk can hold this item.

            Held by a Poison-type, it restores 1/16 of its maximum HP each turn.

            Held by a non-Poison-type, it drains 1/16 of its maximum HP each turn.

Absorn Bulb

Oddish and Gloom can hold this item.

            Holding raises SpAtk, if holder is being hit by a Water-attack.

Leftovers - Thrash Can on boat SS Ann

Snorlax can hold this item.

            Holding restores 1/16 of the max HP at the begin of every turn.

Light Ball

Pikachu can hold this item.

            When this item is being held by a Pikachu, it´s Attack & Special Attack will be doubled.

Focus band

Machop and Machoke can hold this item.

            Holding gives a 10% chance of preventing a Knock Out and keeping the holder at 1HP.

Lagging Tail

Slowpoke (Dragons Den) can hold this item.

            Holding causes the holder to attack as last Pokémon in each turn. Trick Room does not affect
            this item.

Quick Powder
Ditto can hold this item.
            Holding doubles Ditto´s speed stat.


EV-Booster

Macho Brace - Trade with the Biker in Goldenrod
Holding reduces SPD-stat but doubles the gained EVs.


Fossils

Old Amber - Use dig on cracks in Mt.Moon/Rock Tunnel
Old Amber will revive Aerodactyl on Cinnabar Islands.

Helix Fossil - Mt.Moon on the ground / use dig on cracks in Mt.Moon/Rock Tunnel
Helix Fossil will revive Omanyte on Cinnabar Islands.

Dome Fossil - Mt.Moon on the ground / use dig on cracks in Mt.Moon/Rock Tunnel
Dome Fossil will revive Kabuto on Cinnabar Islands.

Root Fossil - Use dig on cracks in Mt.Moon/Rock Tunnel
Root Fossil will revive Lileep on Cinnabar Islands.

Claw Fossil - Use dig on cracks in Mt.Moon/Rock Tunnel
Claw Fossil will revive Anorith on Cinnabar Islands.


Mega Evolution Stones

After Playing 50 Hours and beating Kanto´s Elite 4[not confirmed] you can get a Mega Evolution Stone from the assistant of Professor Oak.
The obtained Mega Evolution Stone will depend on your starter Pokémon.

Venusaurite

Evolves Venusaur into Mega Venusaur.

Blastoisinite

Evolves Blastoise into Mega Blastoise.

Charizardite Y

Evolves Charizard into Mega Charizard Y.

Charizardite X

Evolves Charizard into Mega Charizard X.


Valuable Items

Valuable Items can be sold to the Item Maniac on Route 24.

Nugget/Big Nugget - Route 24 / Use dig on cracks in Mt.Moon/Rock Tunnel
Nugget = 15.000$ , Big Nugget = 30.000$

Tiny Mushroom
Paras can hold this item.
            Tiny Mushroom = 1.500$

Big Mushroom
Parasect can hold this item.
            Big Mushroom = 3.000$


Miscellaneous

Soothe Bell - National Park
Golbat and Crobat can hold this item.
            Holding doubles the happiness of a Pokémon.

Grip Claw
Sandshrew can hold this item.
            Holding makes the moves Fire Spin, Bind, Magma Storm, Sand Tomb, Clamp, Whirlpool, Wrap
            last for 5 turns with a chance of 50%. Otherwise it will last 4 turns.

Deep Sea Scale
Chinchou can hold this item.
            If a Clamperl is holding this item, it will evolve into Gorebyss after a trade.

            If held by a Clamperl, it will double the SpDef.

King´s Rock - Use dig on cracks

This item can evolve certain Pokémon.

            Holding increases the chance of making an opponent flinch by 11,7%.

Everstone
Geodude and Graveler can hold this item.
            Holding this item prevents the Pokémon from evolving.


Special thanks to Agrodark, Axel008, edited by Matzeus