Crystals have many uses. Since ancient times they have been used for healing and as sources of power. Different stones give off different vibrations which can attract or repel different energies. Crystals can be used in Spell-work, Reiki, Meditation or they are lovely just to look at for decoration or adornment. There are many sources available for information on crystals and their uses. I find that it is easiest to start with the use and then determine which stone works . I found a quick and easy reference guide many years ago while surfing the net. Unfortunately, the website is no longer up and running but I want to give credit to amasveritas.com for the list I have included below:
Calming: amethyst, blue lace agate, blue topaz, calcite, emerald, hematite, marble, moonstone, opal, pearl, sapphire & selenite.
Courage: agate, aventurine, blue lace agate, carnelian, cat's eye, citrine, diamond, garnet, jasper, onyx, quartz, sodalite, tiger's eye & topaz.
Divination: amber, amethyst, aquamarine, blue topaz, calcite, diamond, emerald, hematite, jade, marcasite, moonstone, obsidian, onyx, selenite, sodalite, tourmaline & turquoise.
Dreams: amethyst, calcite, carnelian, emerald, jade, moonstone, selenite & turquoise.
Exorcism: amber, amethyst, calcite, cat's eye, diamond, emerald, jade, lapis lazuli, malachite, obsidian, rose quartz, selenite, tourmaline & turquoise.
Fertility: carnelian, diamond, emerald, garnet, jasper, moonstone, opal, pearl & quartz.
Happiness: aquamarine, aventurine, citrine, diamond, garnet, lapis lazuli, quartz, rhodonite, rose quartz, topaz & turquoise.
Healing: agate, amber, amethyst, aquamarine, aventurine, bloodstone, blue lace agate, calcite, carnelian, citrine, diamond, garnet, jade, lapis lazuli, lodestone, malachite, marble, marcasite, moonstone, opal, pearl, peridot, quartz, topaz, tourmatine & turquoise.
Intuition: amethyst, aquamarine,blue lace agate, cat's eye, citrine, coral, emerald, garnet, hematite, jade, lapis lazuli, lodestone, malachite, marcasite, moonstone, obsidian, opal, pearl, peridot, quartz, sapphire, selenite, sodalite, topaz, tourmaline & turquoise.
Love: amethyst, carnelian, diamond, emerald, garnet, hematite, jade, lodestone, marcasite, moonstone, opal, pearl, peridot, quartz, rhodonite, rose quartz, ruby, sapphire, sodalite & turquoise.
Meditation: amethyst, aquamarine, blue topaz, calcite, carnelian, citrine, diamond, emerald, jade lapis lazuli, moonstone, onyx, peridot, quartz, sapphire, selenite, topaz & turquoise.
Money: agate, amber aventurine, carnelian, citrine, diamond, emerald, garnet, marcasite, peridot, quartz, rose quartz & topaz.
Peace: amethyst, aquamarine, blue lace agate, coral, diamond, emerald, garnet, jade, moonstone, opal, pearl, quartz, rose quartz, sapphire, selenite & turquoise.
Protection: agate, amethyst, carnelian, citrine, diamond, hematite, jade, lodestone, moonstone, obsidian, onyx, peridot, quartz & rose quartz.
Have fun choosing different stones to work with. Pick them up, get a feel for them and trust your intuition.