Every Crystal has a unique vibration. Using different crystals for healing purposes can make you feel all sorts of things. Memories you haven't thought about in a while, a tingling sensation, or maybe just a sense of warmth. There can be many feelings associated with holding a Crystal or Stone in your hand, everybody is different. For example, an excellent way to see if a Crystal Pendant is right for you at this time is to hold it in your non-dominant hand and see if it warms up. If it does, thats good for you right now. If it stays cold, pick another one.
Using energy that a Crystal provides can give you confidence, creativity, partnership, abundance, clarity, and even dreams, based on there own unique properties. There are a wide variety of effects that anybody can feel when holding a Crystal.
There are thousands of Crystals that are readily available today. One of the most common is Quartz Crystal. In one way or another everybody as has either seen or held a Quartz Crystal, whether you were drawn to it or felt like they had to have one but were not sure why. In general, White or Clear Quartz is really quite powerful and the most common. This Crystal is used to amplify one's own aura to feel more energy around you. It's known as a "Master Healer" because of the many types, shapes, sizes, colours and their different properties. The picture below is a Channeling Clear Quartz Crystal.
Crystals are used to amplify, clarify, and provide energy. When you have a thought, you can amplify it by using a crystal.
There are a lot of books available on Crystals, their properties, and how they can help you. When you are going to buy some Stones or Crystals, look around the store and see what you're drawn to. Use your senses when examining the Stone or Crystal. The way it looks and the way it feels. You might find the Stone you're drawn to might not look as beautiful as another, but it will absolutely be meant for you!
Lastly, Stones and Crystals are supposed to be used as tools to help the healing process. They don't replace anything. They help in whatever enhancement is needed.