Quartz is an extremely versatile stone. You can literally use it for every spell you can think of, its a great substitute, and can also be used to boost the properties of other stones. You can even place ir in gardens and potted plants to help plants grow. What I have been using my quartz bits as since I've moved out on my own is a crystal grid to protect my home.
I've noticed my aura has a tendency to attract things, and likewise negative bits and things can be found trying to make a home in any place with anyone no matter who you are or where you live. One way I try to combat this is with this quartz point grid. Simply place a piece of quartz on the corners of your property. I keep them in the windowsills closest to the four corners of my apartment. Keep your largest point in the center of your home, and try and refresh or cleanse it often. Even if its simply dusting it off, anointing it with a smidge of holy water, or simply noticing its presence and reminding yourself its there.
I have also found that selenite can be just as powerful as a protection stone, so you can use it instead of quartz if you prefer, or simply inter-mix the two. I keep a polished selenite point at the center of home as the focal point of my grid, and a large unpolished tower as a main piece of my altar. I highly recommend a quartz or selenite grid to anyone, especially if you begin to feel uncomfortable in your home. Do you find yourself running up the stairs or wanting the lights on in every room around you? Try a quartz grid, and call me in the morning.
Places to find them:
-your own backyard!