Tier 1 violet
Crystal type has an violet body color (light, medium, or dark) and violet background. Light crystal body type has Mineral Mania main attack. Medium shade can attack with Diamond Cut. The dark shade crystal is using Gem Toss.
Any Chumbi can wear 6 different crystal coats - Amethyst coat with Refract secondary attack. Crystal Chumbi with Emerald coat have mastered Gem Shard attack. Fluorite coats are attacking with Shimmer Shine attack. Chumbi cloaked in Rose Quartz are wielding Quartz Crush. Ruby coats attack using Dazzling Light. And a plain crystal coat can launch a Glowing Rush.
Crystal strengths are against mountain, frost, and flower Chumbi. Crystal rather avoid conquest against creature and cave. Crystal Chumbi on Opensea.