The electron released from the iron by irradiation is probably taken up by another ion, but there are different models on how exactly the Fe(+4) color center is stabilized. Note that the colorizing iron and its precursor is probably not present in the lattice as ideal ions (Fe 3+ and Fe 4+), but in part bound covalently to oxygen to form a FeO 4 group. The irradiation causes iron Fe(+3) atoms which probably replace the silicon in the center of the SiO 4 tetrahedra to lose another electron and form Fe(+4), an unusual oxidation state of iron ( Lehmann and Moore, 1966). gamma rays from radioactive sources ( Berthelot, 1906) and the presence of iron built into its crystal lattice ( Holden, 1925). Amethyst shows a weak dichroism, with the color changing from gray-violet to purple.ДЄmethyst owes its color to high energy radiation, e.g. Very often the color is unevenly distributed or even patchy, and is most intense at the tips of the crystals. The color can vary from a pale pinkish violet to a dark blue-violet, with shades of red, and sometimes gray. Although it occurs in many different rocks in many different forms, most amethysts share certain basic properties, not just the color. This association probably came up because of the color of red wine is sometimes similar to that of amethyst.ДЄmethyst is a very special quartz.

The name refers to its alleged ability to protect its owner from the negative effects of alcohol consumption, namely 'methy', the Greek expression for being drunk, and 'a-methy-stos' would translate to 'one that does not get drunk'. Before these resources were discovered, most amethyst was mined in Sri Lanka, India, Germany (Idar-Oberstein region), and the Ural Mountains (Murinska gem region) in Russia. Today most amethyst comes from Brazil and Uruguay. The violet to purple amethyst is the most important and best known gem variety of quartz and has been used for lapidary works since ancient times.

Amethyst geode