Crystals
A Crystal is extremely well-organized molecular structure. In a crystal, all the atoms (or ions) are arranged in a regular grid pattern. Jewels, pencils and snow, all have this in common, they are all crystals.
Different minerals have different molecular compositions, there’s a big difference between say an Amethyst crystal and a salt crystal, obviously!
The philosophy of modern crystal healing is based on traditional concepts borrowed from Asian cultures, most notably the Chinese concept of life-energy (chi or qi) and the Hindu or Buddhist concept of chakras, which are vortices of this life-energy, said to connect the physical and supernatural elements of the body.
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What I would say is just follow your intuition. My personal belief is that crystals can be used in healing, because, they have unique vibrational frequencies that interact with the body's energies to restore balance and harmony. You can feel it. Crystals emanate the love vibration, and love heals!
Connect with your Crystal
Crystals naturally emit energy; crystal healing is an alternative medicine technique that is supposed to tap into this natural healing energy. Holding crystals, or placing them on your body, is thought to promote physical, emotional, and spiritual healing. Crystals supposedly do this by positively interacting with your body's energy field, or chakras, channelizing your energy levels, thereby focusing on healing your body from the inside. The same interactive process continues with crystals that you have placed within your space, or around your physical body and your Aura. As with all spiritual tools, I believe the power of crystals is not dependent on a time frame, but rather on one’s commitment to their use. However, the more time you spend learning their unique powers and using them during meditation etc., or with the intention to bring healing, the faster they will provide healing benefits.