Amethyst

Group: Quartz Mineral class: Oxides Colour violet, purple, purple-red, light purple Colouring substance: iron Pleochroism: very weak, purple, grey-purple Mohs’ hardness: 2.65 Density: absent Fracture: conchoidal, very porous Crystal system: trigonal, prisms with 6 facets Transparency: transparent Lustre: vitreous lustre Fluorescence: weak, green

The Amethyst is characterized by its purple colour, which can be more or less intense. By the third millennium BC, in Egypt and Asia Minor, it was considered as one of the most important stones in the array of jewels and other precious objects. The Ancient Greeks believed that the Amethyst had important curative powers against alcoholism. From that characteristic may have originated its name, which, in ancient Greek, means ‘not drunk’. The Roman naturalist Plinio, on the other hand, considered that the name comes from its colour, similar to that of some red wines. However, the most important meaning for the Amethyst comes from its religious and sacred ambit. In the Bible, it is one of the 12 stones which represent the 12 tribes of Israel. From the Middle Ages (and still today) it was considered the gemstone of Cardinals and Bishops, meaning peace, humbleness and chastity.

The Amethyst is a violet-purple variety of quartz. It is composed of silicon dioxide and crystallizes in triangular form. The colour of the stone, produced by the presence of minute quantities of iron, is sometimes distributed irregularly or parallel to the surface of the crystal. If heated up to 400-500C, Amethysts change into a brown-orange colour and become citrins

Generally found in ‘deposits’ in Brazil, Madagascar, Zambia, and Uruguay, as well as in India, Burma, Canada, Russia, Sri Lanka and the USA.

Most clear and colour intense Amethysts are cut as circular stones or oval cut. Sometimes as well brilliant cut. Varieties with little or no transparency are cabochon cut.

With beryl, topaz, tourmaline, coloured glass.