The name quartz comes from a slavic word meaning “hard”. Rock crystal comes from the Greek “krystallos” meaning ice, because the ancients believed that it was “eternal ice”.
It is a mineral, often regarded as a rock as it is widespread in various aspects and sometimes as a gemstone, rock crystal is the variety most prized by gemologists, jewelers, sculptors and art objects.
The smoky quartz is brown to almost black, or black (morion quartz), the latter coming from a natural or artificial irradiation with gamma rays.
Yellow quartz is called citrine and purple quartz amethyst.
The prasiolite (or prasolite) is a non-natural colored quartz, so named after the Greek “prason” for green and “litho” for stone, as it is leek green, and obtained by heating to 650 ° C an amethyst or a yellowish quartz from Brazil.
Rose quartz : its color is due to nano-fibers of dumortierite in massive rose quartz, while for crystal rose quartz color is due to natural radiation, the pink color may fade. It may present a phenomenon of asterism due to very fine inclusions of rutile.
The binghamite is the trade name for a variety of quartz with gray-brown speckle effects when cut cabochon.
Quartz is the standard of hardness 7 on the Mohs scale, which counts 10.
Quartz was used because of its hardness since prehistoric times to make tools and weapons in France and Ethiopia (dated more than 2 million years) and scrapers and arrowheads were placed in tombs in China already over 600,000 years ago. During the Neolithic in the Far East and India, it was already known how to drill it and mount its fragments for necklaces. Later, in Sumer, quartz was present as amulets, seals, items of adornment. The Egyptians used it to make statues of their gods, vases, would encrust it in their jewels and served as “living” eyes for their statues. Subsequently, all civilizations including the Greeks, Romans, Hindus … used quartz.