Crystal Quartz or king quartz is a must in your crystal collection! 
It connects to all of the chakras and it brings a sense of calm and lots of energy.
Crsystal Quartz doesn't hold on to energy making it easy to mantain and to recharge.
Every crystal has a more specific intention and purpose, but crystal quartz is able to work with any kind of energy and it can be activated to serve you in any way you decide, that's why is called king quartz and though ver y common, it's amongst the most populars and MUST have. 
Due to the fact that each and every single crystal is unique, the size will slighty vary from the one the model is wearing. Size of the crystal ranges within 2"-3".