I'm actually not experienced with working with crystals, but I know people who do regularly. From my discussions with them- you shouldn't force a connection between yourself and a stone/crystal. A crystal/stone will "apparently" choose you, and when it doesn't it can be dangerous to use. It's good to know that your natal chart can determine which crystals/stones are safe to use, "apparently" some crystals can react and cause serious health issues. The new age culture of hoarding crystals/stones without any research on compatibility is ineffective and perhaps even dangerous.
You can find unreliable crystal information online so it's best to check yourself. If you feel the crystal isn't resisting a connection with you, you can just cycle your energy into the crystal and back out into you, in through one hand and out the other is typical, observing the energetic qualities of the stone/crystal. If you can't preform this, you probably shouldn't be using crystals/stones.
You'll probably notice that stones and crystals can be an unusual shade and also have a difference in transparency. From what I'm told, colour and transparency are important factors. Because of impurities, crystals and stones have to be considered on an individual basis. Transparency apparently improves energy conductivity and therefore more powerful, probably because a transparent crystal will be more pure than a clouded one.
