Investigating the strange ice is one of the first things you'll need to do when you visit Dragonspine in Genshin Impact.
Dragonspine, the snowy mountain located between Mondstadt and Liyue, is a place with harsh climate, special mechanics, and lots of secrets to uncover. You'll receive the "In the Mountains" quest, which asks you to investigate the strange ice, by talking to Iris in the Adventurer Camp.
Follow the quest marker to find the strange ice, which will appear as a shimmering blue crystal. Unlike typical ice, it won't break if you attempt to melt it with pyro, nor can you destroy it with weapon attacks.
To break the strange ice, you'll need to use a type of ore found only in Dragonspine: Scarlet Quartz. These red crystals break upon impact like any other ore deposit, and drop a quartz that you can pick up. If you attack the strange ice with a scarlet quartz on you, you'll be able to deal damage to the ice.
How to Investigate the Strange Ice in Genshin Impact
Scarlet Quartz will disappear after a short period of time, or if you use a Teleport Waypoint, so you cannot transport them over large distances.
To break the strange ice for your mission, you'll need a total of four Scarlet Quartz, all of which can be found in the vicinity. To reach one of them, you'll need to defeat a Frostarm Lawachurl. Once you break the strange ice, you'll see a shard fly to the peak of the mountain, and you'll unlock the Frostbearing Tree, the main source of rewards in Dragonspine.
Breaking the strange ice will unlock the rest of your journey to the peak of Dragonspine, which - spoiler alert - involves thawing out more shards. Read our guide for a full walkthrough of how to complete this quest!