Clear quartz is the most versatile crystal in the world and can be used for any and everything. Fill it with whatever intention you need it to have, and it will do the job for you. It also amplifies other crystals. Just make sure you cleanse it periodically to clear out old or unwanted energy before you use it for a new working.
 
This is a natural product, and each piece is unique. The image is representative of the product you will receive but is not a picture of the product itself. These particular pyrite pieces have some oxidiziation and don't have the luster you find on some pyrite. This is natural and doesn't affect the metaphysical properties of the stones.