Quark Corundum Farm

Observer → Repeater (2 ticks) → Redstone to piston.
When corundum grows, piston extends, breaks the gem, retracts.

Before we dig into the farm, we need to understand the ore itself. In Slime Rancher 2 (Update 0.5.0+), Quark Corundum is a prismatic, spiky mineral that glows with a soft quantum haze. It is classified as a "Rare Export" resource. quark corundum farm

Primary Uses:

Layer by layer (from bottom up):

Y+2:  Air (cluster grows here)
Y+1:  Budding Corundum Block (facing up)
Y+0:  Piston facing up + Redstone clock beneath
Side: Water stream flowing into hopper line

How it works: