Crystal are essential components of many technologies. You'll probably be surprised to learn that crystals are powering devices that you use every single day. This list is full of uses for crystals. They are key components in machines which are necessary for our health and our modern communication methods.Then there are also the "new age" uses for crystals. The jury is still out on whether crystal healing works, but there are lots of people who swear by it. Take a look at this list and decide what you think.
Ultrasound waves are sound waves that bounce off of surfaces and come back in the direction from which they came. Humans can't hear them, but we can use them to see inside the human body, and we make ultrasound machines using crystals. When you send electricity through a crystal, it vibrates, producing ultrasound waves. Crystals can also detect ultrasound waves coming back to them - if an ultrasound wave hits a crystal, a burst of electricity will flow through it.
Satellites use the same kind of quartz crystal oscillator that watches use. The crystal vibrates when an electric current passes through it, and that vibration is used to produce a precise frequency - the mechanism for satellite communication. Satellites are used for communication between aircraft or spacecraft, and stations on the ground.
Quartz crystals are what keep watches running without requiring a new battery. A watch battery sends electricity through a quartz crystal, and the crystal then oscillates. These oscillations are converted into even more electric pulses, which either power a digital display or drive an electric motor which spins the clock's hands.
Sonar is a type of ultrasound system which is used by ships and submarines for navigation. A submarine will send out an ultrasound wave and wait for it to bounce back. The submarine can determine whether there are any nearby vessels or obstacles, based on how long the sound takes to bounce and return. Sonar waves are produced the same way that the sound waves in a medical ultrasound machine are produced.