Scarlet Quartz is an item found in various regions throughout Dragonspine. It has special effects on the character when picked up, and cannot be obtained as an item through normal means. As such, it does not count for the "Mine 10 items" Battle Pass mission.
When picked up, it will reduce 5% Sheer Cold accumulation, halt all Sheer Cold accumulation, and imbue the character with its essence, until it is used up or after 25s where the imbuement dissipates. The next time the character (or another character in the party) hits an entity, that hit will be imbued with the Scarlet Quartz, dealing a separate hit of substantially high Pyro DMG alongside the regular damage to the enemy, consuming the imbuement in the process. Its main use is to destroy unique ice such as Ancient Rime and Frost Thorns which are immune to all damage except that from Scarlet Quartz, by consuming the imbuement to deal damage to it.
Scarlet Quartz is similar to natural ores. It spawns near rock, and often with a rock body behind it. It is considered a Geo object similar to White Iron Ore and Starsilver, subjecting it to standard damage multipliers for its category ("heavy" attacks like Geo attacks, claymores, and plunging attacks with melee weapon users will destroy it instantly).
As Ancient Rime can only be melted with Scarlet Quartz, Ancient Rime will always have Scarlet Quartz nearby, although occasionally the Scarlet Quartz will be far enough that after picking up the Scarlet Quartz, the player may find it easiest to land an attack using an Aimed Shot from a Bow character.
Scarlet Quartz found in the open world will respawn after 15s, unless they are involved in a puzzle, in which case the ones involved will only respawn after the puzzle is completed with the specific Scarlet Quartz in the vicinity that are used in the puzzle.
This item is not used in any recipes, but as mentioned above, it has special properties.