Unless one considers water a mineral, it can be safely said that quartz is the world’s number one most common mineral. It accounts for approximately 12% of the earth’s continental crust, and is made simply of silica and oxygen. The name “quartz”; is probably originally derived from the Saxon word querkluftertz, which means “cross vein ore”. It was believed by early civilizations to be permanently frozen ice, and has actually been used in jewelry and decorative applications for upwards of 4000 years. Before that, it was used to make tools and weapons. In the Medieval Era, quartz was used for crystal balls, and its powers of disease diagnosis and clairvoyance were acknowledged even by many cultures outside Europe. Perhaps the mother of all gemstones, quartz manifests itself in many varieties that include chalcedony, agate, aventurine, and jasper.
Generally, there are two kinds of quartz: macrocrystalline and microcrystalline (or cryptocrystalline). These distinctions refer to the size of the crystal grains that compose the stone’s structure. While macrocrystalline strains of quartz are made of discrete crystals that are visible to the naked eye, it is very difficult to see the same “building blocks” in microcrystalline quartz varieties, even with a microscope.
Quartz is still largely associated with the massive, beautiful rock crystal forms that have given great inspiration to spelunkers and geode aficionados. Some naturally occurring quartz crystals can even grow up to 7 metres in length and weigh hundreds of kilograms. Metaphysical characteristics of quartz are thought to vary depending on the specific variety in question, but generally include heightened powers of insight and emotional stability.