For a visual walkthrough of all the ores added by the mod and how to find them, check out this guide: Calamity Full Ore Guide TTVObama2831 YouTube• Jun 5, 2023 Ores - Official Calamity Mod Wiki
Spawns Hallowed Ore in the Underground Hallow. Calamity-Specific Hardmode Ores terraria-calamity-hardmode-ores
Spawns Tier 2 ores ( Mythril and Orichalcum ). For a visual walkthrough of all the ores