Quartz
Quartz is the most common mineral found on the surface of the earth. A significant component of many igneous, metamorphic and sedimentary rocks, this natural form of silicon dioxide is found in an impressive range of varieties and colors. There are many names for different varieties: Crypto-crystalline varieties of Quartz are listed separately under Chalcedony, and include the Agate family.
Of the many varieties of quartz, the most popular for jewelry are amethyst, blue quartz, chalcedony, citrine, milky quartz, rose quartz, rutilated quartz, and smoky quartz.
Magic & Myth
Radiating the white light energy of the Universe, clear quartz crystal is light made solid. Quartz clears and amplifies the thoughts. It focuses and stores energy and information. It can be used to clear and activate the chakras, for purification, healing, in meditation and trance work, to dispel negativity, enhance and seal the aura and for many other uses. Quartz can be used in any and all workings. When in doubt or when lacking the "correct" type of stone, quartz can always substitute.
Wearing quartz with the point facing upwards, opens the upper chakras, and facilitates meditative states and psychic awareness, but can leave the wearer feeling somewhat spacey, so it is not recommended for prolonged duration. Wearing it point downwards helps to ground. A double-terminated crystal (one with a point on either end) worn horizontally can help balance left/right brain. Vertically, a double-terminator can help incorporate both the spiritual and the material into the wearer's life. The many configurations and types of quartz crystal are too numerous to list here.