Quartz: Properties, colour and information

Naming of quartz

The name “quartz“ refers to a group of minerals with the same chemical composition and physical properties. The origin of the term is probably from the Saxon word "Querklufterz" for "cross-veins-ore", in reference to the localities. Another possible origin of the term “quartz“ is the Slavic word for "hard".

Chemical composition of quartz

“Quartzes“ are silicon dioxides, which are divided into two subgroups: For microcrystalline quartz crystals such as amethyst, falcon eye, white quartz, etc., the individual crystals are visible to the naked eye. Microcrystalline quartz such as agate, jasper or carnelol e.g. however, have microscopic crystals and thus form their own small family.

History of quartz

“Quartz“ has been demonstrably used since the beginning of humanity, first of all as a tool - the hardness of the quartz (Mohs hardness scale: 7, diamond: 9) is well known, the term "quartz" probably goes back to the Slavic word for "hard". Regarding the origin of the name, however, there is still disagreement. Quartz was used as a knife, arrowheads or even flints. In addition, rock crystals ("white quartz") were already worn as amulets in the Neolithic period. The seemingly magical effect of quartz is also visible in the long tradition of the so-called "crystal balls". In addition to this practical use, quartzes have been worn for thousands of years even as jewellery gems, mostly honed as cabochons. The multiple and varied use of quartz may explain why quartz (crystalline silica) is the second most abundant mineral in the earth's crust after feldspar.