Skylanders Spyro's Adventure soul gem locations guide

Gem #23: Molekin Mine

Unlocks: Cynder’s “Haunted Ally” Ability

Early in the level, you’ll enter the Underground Lake area. The Soul Gem is to your left in the water, but you can’t reach it just yet.

Continue forward until you reach the locked door. Turn left and start chipping a path through the rocks with your pickaxe.

Make your way around the mechanical mining enemy and keep heading south.

This path will lead you to the water. Switch to Gill Grunt and hop in, and you’ll quickly spot the Soul Gem resting on a rock.