I have been working with crystals for some time, and I found personally that some crystals do work better on certain chakras, areas of the body and specific issues, crystals are a lot like people they do have things that each crystal are better at is just a matter of getting to know crystals better.
when working on people I have to be very careful, crystal work can be very powerful and intense. I have met people who are Extremely sensitive to crystal energy, just being in the same room with a large number of crystals brings on a healing reaction and I have to be careful not do more than each individual client can handle.
For those attuned to the master level I suggest passing an attunment on a crystal when you first get it, the beings that inhabit the crystal love reiki and having reiki attuned little helpers ( crystals) around can be a great thing from time to time!!