In Paulo Coelho's The Alchemist, the crystal shop may be symbolic of where Santiago finds himself in the pursuit of his Personal Legend. In one interpretation, we might see that the crystal acts like a window, allowing Santiago to see what might lie ahead of him. It is here that he learns from the crystal merchant what can happen when one does not "seize the time." The merchant also had a dream, his own Personal Legend to travel to Mecca. However, he puts it off, builds a business (which he cannot leave) and by the time he can afford to go, he is too old. This disappointment can be Santiago's if he loses faith, so the crystal could be showing him what life might look like for him. However, it would be important also to remember that when looking through crystal, the image on the other side is distorted, so this would suggest that Santiago would have to decide with his heart, and not by what he sees…or hears, for the crystal merchant does not encourage the boy in his quest.
The crystal shop might also be symbolic of "all that glitters is not gold." Crystal has long represented "wealth" because it was so hard to make and only the very rich could afford it. From a distance, the crystal shop stands out, and the light that reflects off of the clean and sparkling crystal draws passersby to shop, and later to drink tea. The merchant says to Santiago:
Business has really improved…I'm doing much better, and soon you'll be able to return to your sheep. Why ask more out of life?
The boy responds that he must follow the omens. The merchant understands this concept, but does not understand Santiago's desire to visit the Pyramids. He says:
I don't know anyone around here who would want to cross the desert just to see the Pyramids…They're just a pile of stones. You could build one in your backyard.
In some respects, the crystal merchant is telling Santiago that "this is as good as it gets." He tries to dissuade the boy from pursuing his dream. If Santiago allowed himself to be taken in by the merchant' perceptions (a theme in the book), along with the lure of the commission (a good one as the merchant had not expected Santiago to be successful), he would have stopped his journey there. However, the attraction of selling crystal has been missing since the boy's first day on the job…
…it wasn't exactly the kind of job that could make him happy.
And ultimately, Santiago knows himself well: he wants to be on the move. He still believes in his Personal Legend, even though he does, at times, have his doubts. However, when the time comes to make his decision to move on or return home, he thanks the crystal merchant, asks for his blessing, and—receiving it—moves forward toward realizing his dream.