What are your opinions / beliefs about the mystical powers of gem stones and crystals?

Lots of questions… just pick one if you like.

If you’re a spiritualist and/or religious person who is philosophically and/or theologically opposed to the belief in the mystical powers of stones and crystals, why? What’s your opinion of people who believe in such things?

If you use stones and crystals as part of your spiritual practice, please describe how and the benefits of such use. What are your favorites?

If you’re an atheist and/or scientifically-inclined person, do you think the so-called healing powers of gem stones and crystals are legitimate? Why or why not?

About me:
I am a spiritual person who does practice a religion. I was taught to believe that mysticism in the hands of non-God-fearing individuals can be a very dangerous thing. Consequently, I had been fearful at times of those who use such things as part of their spiritual practice. Over the years, my opinion has changed. In my opinion, I believe the earth belongs to God; therefore, God can use whatever He/She/It wants to stir, heal, settle, etc. anyone. I do not believe in the objectification of such elements, but I do believe in their use as tools for achieving desired results. Personally, I do not have any crystals in my collection of stuff. However, I do have a tiny collection of stones – this collection helps me to feel grounded. I like the feel, the sensation of holding such stones when I’m meditating (which unfortunately hasn’t happened in a long time). The idea of gem stones having healing powers is intriguing to me, but I’ve never experienced it.