The Crystal Core is an item in Genshin Impact found only in certain locations. Not only does it look mesmerizing, but it's also a material used to craft Condensed Resin to acquire more rewards when completing Ley Line challenges, so it's important to know how to gather them.
Crystal Cores do not spawn on the ground, however, as they can only be obtained by catching Crystalflies, which introduces other obstacles. Here's a guide on where to find Crystal Cores in Genshin Impact.
Genshin Impact Crystal Core Location Guide: Where to Find
As mentioned earlier, Crystal Cores can only be obtained by catching any type of Crystalfly in the wild. Crystal Cores aren't sold at shops.
Crystalflies themselves are fairly rare to find as they only respawn every two days in real-time as long as it's not raining. Since it doesn't rain in Dragonspine, Crystalflies are guaranteed to spawn there. It is recommended to look for Crystalflies during the nighttime as it will be easier to spot them since they glow.
Crystalflies will also run away when you get close to them, so it's advised to use Sayu since she has the passive skill to not startle wildlife.
For the specific locations to farm Crystalflies for Crystal Cores, feel free to check out the Teyvat Interactive Map.
In general, there are plenty of Crystalflies to be found in Monstadt, Liyue, Sumeru and Inazuma.
For more on Genshin Impact, feel free to check out some of our local specialty guides on where to find: