Special summons a Gem-Knight monster from the deck
Tributes himself to use effect.
Must be on the field to use effect.
Gem-Knight Normal Monsters
Here are the Gem-Knight normal monsters you can special summon with Gem-Knight Alexandrite. If you need a big Beater Gem-Knight Crystal is the best choice. For fusion summoning, special summon any Gem-Knight to fit the fusion requirements.
Since you will most likely perform a fusion summon with the monster you searched, here are some other cards that may help. Fusion Recycling Plant can recycle 1 fusion material monster to your hand, and also search for Polymerization from your deck. King of the Swamp can be treated as 1 fusion material required for Fusion Summon, and at the same time it also can be used to search 1 Polymerization from your Deck. Fusion Sage can search 1 Polymerization from your deck. Fusion Reserve allows you to add 1 of the Fusion materials listed on the Fusion monster to your hand, and add 1 Polymerization from your Graveyard to your Hand.
Use Gem Enhancement if you want to search your deck further. Tribute the special summoned monster to revive Alexandrite, then use Alexandrite’s effect again to search another Gem-Knight monster. This could also be a way to load your graveyard to retrieve Gem-Knight Fusion multiple times