Quartz is the most common mineral in the Earth’s crust. It appears nearly everywhere: in the desert, rivers, partly in the sand of the seas. It is the collective noun of the following minerals:

         1.      Amethyst= violet

2.      Golden Quartz= goldish

3.      Citrine= yellow

4.      Smoke Quarzt= smoky, brownish-black

5.      Rock Chrystal= waterclear

6.      Blue Quartz= blue

7.      Chrysoprase= apple-green

8.      Cat Eye= reyish-green

9.      Rose Quartz= pink

10.    Eagle eye Quartz= bluish-grey

11.    Tiger eye Quartz= golden yellow, brown

 Mohs: 7.