Quartz is the second most abundant mineral and is made up of Silicon/Oxygen - there are many different varieties of quartz, some of which are classified as Gemstones.

They range in colour from clear through just about the entire spectrum to black and if they are pure, are rated 7.0 on the Mohs hardness scale.

The major gemstone types are Citrine, Roze Quartz and Amethyst.

Examples of Quartz are shown below.