A typical Crystal Planting Kit (2 Crystals) contains components to grow two distinct colored crystals, usually featuring two packs of crystal growing powder, two seed rocks or base crystals, measuring/mixing containers, a stirring stick, and step-by-step instructions.

Expermental Principle of crystal planting 

As the hot saturated solution cools, due to changes in solubility, the solution precipitates out as a crystal, a process called crystall.