In Chapter 19, Baba tells a story about a gem and a stone. What is the meaning of this analogy?

The analogy of the gem and the stone, found in Chapter 19, illustrates what a Guru expects from a disciple and why disciples may have different outcomes despite receiving the same guidance. In the story, both a gem and a common stone are rubbed on a whetstone. While both are polished, the gem becomes a brilliant jewel, whereas the stone simply becomes smooth, unable to gain the gem's luster. Baba uses this to explain that while a Guru provides the 'polishing' process, the disciple's inherent quality determines the result. The qualities a Guru looks for are the disciple's own wisdom, "strong faith at the Guru’s feet and the strength of courage which is patience." Without these, a disciple is like the stone, unable to truly transform.