To charge and purify crystals and stones: hold one in your projective hand (the hand with which you write), and visualize sending white light into it, to purify it, and then, focus energy into it, like that, while thinking of what you want it to do, and/or saying some verse out loud about that. You can also bury them in the earth for 3 days, or hold them in moonlight (usually, full moon) or sunlight (moonlight is perferred, or they could fade in color), or hold them in running water, or placed them in bowl of salted, blessed water, to purify them, also. Though, it's said not to set them under florescent lights, or keep them in salt more than once.

Crystals are like solid friends that can help you on your spiritual path. You can wear them as some type of jewelry, you can find crystal pyramids, or spheres, too, and they can be placed under one's pillow at night (the calming ones, anyway), or used to ring around candles (for extra energy to magick), or used to mark a sacred circle, or placed at each of the four cardinal points (north, east, south, and west), or placed over your chakra/energy centers, and used in any meditation, or added to a sacet pouch, or a charm bag, or to a bath pouch, and they're mostly all good for enlightenment, and so on. They can dissolve, and/or remove, certain negativity, also, when you use the right stone, or the right stone for you. There's also Bach essence remedies using stones' powder, like flower essences (they're not for everyone, per se, but probably worth a try, IF you really want to work on some personal problem). You need to try different stones, and see which work best for you, personally. You can also try various metals.

Basic, Magickal Uses, Listing:

Amethyst -- lavender in color, can be clear lavender; healing, dissolving depression, dreams; though, this won't react well with everyone

Bloodstone -- green stone with red flecks; protective; energy; immortality

Blue Lace Agate -- light blue; calming, healing, innocence, happiness

Carnelian -- mostly orange; energy, sun qualities, health

Clear Quartz -- clear; great, all purpose stone, good with all chakras, very absorbent, use under pillow at night for great dreams, and better sleep, with moonstone, often used in healing, especially with moonstone; makes a great talisman or pendant; astral travel; and especially placed on Third Eye Chakra (center of forehead) during meditating; and so on

Diamonds -- ok, you know what they look like from TV, um, sparkly, clear; purity, commitment, higher truth, enlightenment, innocence

Gold -- gold, shiny; strength, masculine, increase wealth, solar

Hematite -- shiny, looks like solid liquid-mercury; very protective; major physical healing; earth element stone; very grounding; use for grounding, held in hand for that (whichever hand feels best for you); i.e., hold a piece of hematite in your hand and feel your connection to the Earth

Kunzite -- white-like stone; memory, past life memories, and regression work; a stone of the element of Earth; a little expensive, or whatever

Lapis Lazuli -- bluish, flecked bluish, stone; great stone, sacred to the Egyptian goddess Isis; can be added with most positive magick; talismans, jewelry; sacred rites

Moonstone -- light cream-white color, with light clear bands, generally; held at throat area for calming sadness and easing anxiety (truly works very well); great as a neck pendant; used to help heal depression, and nervous conditions; calming, peace, comforting; dreams, lucid dreams

Onyx -- black, usually shiny; use to decrease sexual feelings, to suppress them (it's said not to do that forever, though); protection, grounding

Pearl -- shiny, creamy-white, silvery, round; associated with the moon, and the Goddess; deep commitment, soft love, feminity, lunar magick

Rose Quartz -- light pink, can be clear pink; the "love stone," love, romance

Ruby -- red, clear; sex, arousal, increase sexuality, attraction

Rutilated Quartz -- like clear quartz, slightly "tan," and has lines through it, very cool, but hard to describe; much like clear quartz, a little more activity, though, so to speak

Silver -- silvery; definitely associated with the moon; full moon rites, divination, psychic powers, water scrying (place a piece of silver in a bowl of water, and gaze at it), moon rite/ritual magick

Smoky Quartz -- brownish, grayish, sort of clear, smoky color; to rid of depression, when used with clear quartz and/or moonstone, too

Turquoise -- blue; healing, water magick, creativity

A couple other stones, etc.: Topaz, Agate (various types), Jade (green), Copper (copperish), Iron (dark; of Mars, energy), and more