This is a bit of a guide to using crystals for dreaming, lucid dreams and astral projection.
You may or may not be aware, that the colour of the crystal relates to the same coloured chakra. The chakra's follow the colour of the rainbow - red, orange, yellow, green, blue, indigo, violet. So if we want to say improve digestion we would use a yellow coloured crystal as this relates to the solar plexus (yellow chakra for stomach area). For dreaming, we want to use preferably indigo or violet crystals to stimulate the head region. Note that, a crystal which is white or clear relates to the chakra above the head (connection with the divine) and a black crystal relates to the chakra below the feet (connection to earth). Hence why black crystals are the best for grounding, and clear crystals like quartz can be extremely energizing (not ideal when trying to sleep).
There are 3 specific crystals I'd like to discuss in relation to dreaming without mentioning their other numerous benefits:
1.) AMETHYST: this crystal will improve overall dreaming, dream recall and sleep health.
2.) LEPODILITE: this crystal will help with lucid dreaming in particular.
3.) IOLITE: this crystal will help with astral projection, shamanic voyages and visions.
It's best to get a necklace which you can swap crystals in and out, so that you can experiment with different ones and also because wearing the same crystal more than a couple of days can have some negative impact on yourself. For example, the first night I wore an iolite crystal I had an intense astral projection experience when I hadn't AP'd in ages, and I felt a bit drained afterwards. If I were to have this kind of experience every night, my sleep quality would suffer and it would run me down over time. Another example is a time I wore angel aura quartz, which has an energizing effect that makes it difficult to sleep wearing it. It would make me super active during the day, but at night I would get hardly any sleep and struggle getting to sleep. I've noticed all crystals have their negative impacts if wore for long periods, one aspect will be great but it will have an impact on other areas so be wary of this.
Many people say to cleanse crystals under water, and charge them in the sun or moonlight or on top of an amethyst cluster. I've found a quicker and much simpler method of charging them, which is to place them in the freezer for some time. It makes sense when you think about it, because it's almost like a cave environment for the crystal and the cold will exert pressure inside the crystal causing it to release its goodness :)
Hope you enjoyed, please share your experiences if you have any.