There is too much supposition and fallacy promoted without testimonial or feedback in the new-age movement of today. I often cringe when I read some of the books that make such dramatic and seemingly contradictory claims about crystals or gems. Unfortunately suppositional fallacy is here to stay, and we'll have to live with it. But the damage it does in closing down the more empirical thinkers who investigate this science, is the same type of thing that happens in religion when fundamentalist believers blindly push their faith without calm reason predominating. Purveyors of mantras, pujas, Bach flower remedies, essential flower oils, homeopathy, and a host of seemingly subtle vibration mechanisms have been making dramatic claims for years.
Gems are just another item on the list.
However, they endure the investment of time, unlike the other more transient mediums. A gem investment not only generally gains in monetary value, but can be used daily for the rest of your life, and it can travel on for generations. Of course, their are many scientific laws for a happy and healthy life. Gems have a way of helping us to strengthen our resistance to past negative karma returning to us in this life. The wise will select all that is simple and practical for them to attain their goal.