Amethyst
Amethyst is the purple variety of the mineral quartz (SiO2).
Etymology and history
The origin of the name from the Greek αμεθυστος ( amethystos ) - " the intoxication antagonistic " - expresses the ancient belief that a carrier of amethyst was immune to the intoxicating effects of wine. Likewise, should not make wine drunk from a cup of amethyst. Originally, there was this ( But ) belief in the custom of the ( red ) to dilute wine with water, which is then a reddish -violet ( amethyst ) assumed staining. At the same time, of course, you could drink much more of it without getting drunk equal or even having to suffer a hangover.
Another variant of the naming is that Bacchus, the god of wine, a young girl so frightened that it solidified into crystal. Then sighed the God, and as his breath touched the stone, he colored this purple like the color of the wine.
The Amethyst was also rumored to have an apotropaic effect against theft. This fact is evidenced by prehistoric grave finds. Merovingian Period graves with Amethyst show, if at all, Beraubungsspuren not in the area of laying the stones (necklace ), also not if some golden jewelry pendant were also to be found here. Perhaps there was in this era of the early history of more stringent ( and no longer reconstructable ) reputed (negative ) effect of amethyst on the thief.
The amethyst is part of the Episcopal ring.
Color
The purple color of amethyst ranges from a very light, slightly pink to a very dark purple.
The distribution of the color in the crystal is usually irregular. More intensely colored are usually crystal sectors, which are parallel to the { 10-11 } Hauptrhomboeder. There, the violet color concentrated in thin dark purple bands parallel to the { 10-11 } and { 01-11 } rare - surfaces.
In these sectors, amethysts have an irregular, feinlamellare twinning after the Brazilian law and the intensely colored planes mark this twin planes.
Color-giving are lattice defects, with a Fe4 ion in tetrahedral coordination, that is surrounded by four oxygen ions, so-called [ FeO4 ] - centers. It is still controversial whether these defects occur on the silicon position ( Fe4 replaces Si4 ) or interstitial ( Fe4 in a normally empty tetrahedral site in one of the 6-sided channels of the quartz structure).
These defects result from defects with Fe3 in a tetrahedral site by irradiation (eg from radioactive decays ). This radiation removes an electron from the Fe ion and ionized so Fe3 to Fe4 . The required to produce the amethystine radiation dose is generated, for example in granitic rocks alone by the decay of naturally occurring 40K isotope in about six million years ago.
Amethysts can be generated from colorless Fe-containing crystals by artificial X-ray irradiation, for example, in nuclear reactors.
Under the influence of sunlight lose their color amethysts quite quickly. The stones should therefore be exposed to direct UV irradiation.
On heating amethysts lose their color also. They develop a Citrinfärbung mostly caused by submicroscopic Eisenoxidentmischungen, and more rarely a green Prasiolithfärbung or completely colorless.
Education and Locations
Amethyst is a common mineral; large and clear specimens that are suitable for processing as a gemstone are limited to comparatively few localities. Deposits are found in Brazil, Uruguay, Namibia, Madagascar, Russia, Sri Lanka and Morocco. Such crystals are found primarily in cavities in hydrothermal veins and in volcanic rocks. Often the commercial species are the so-called Amethyst, where the crystals have formed within a cavity surrounded by a layer of chalcedony. Most Druze come usually from Brazil and can be high as a man.
A well-known German locality is the Steinkaulenberg in Idar -Oberstein. The unique and well-known blue - violet color is given there by the metals in the mountain massif. Having found huge deposits in Brazil and these crystals can also be colored, of mining in the Steinkaulenberg. The mineral mining is now prohibited there. The site can be viewed as a show mine.
Europe's largest amethyst is located in the Lower Austrian town of Maissau. The discovered about 150 years ago the Amethyst by reference Maissau located about 60 km north- west of Vienna, 1 km after the village Maissau at the Horner Road towards Horn. The occurrence in Maissau has a secure course of about 400 m, of which approximately 40 m in the open accessible viewing tunnel, shows a maximum width of 2 m and is nearly perpendicular (to drop between 80 and 90 ° to the SSW and NNE). The first excavations were targeted in 1986 under the supervision of Krahuletz Museum Eggenburg instead. As of 1999, the systematic excavation of the passage through the corn Amethyst Auer -Gesellschaft ( MAG) began. This impressive disclosure of Amethystganges in the Amethyst Maissau is unique worldwide. In addition, a continuation of the aisle are suspected over a distance of 1 km.
Another rich amethyst is known since the 19th century on the cemetery of Eggenburg. Already Johann Krahuletz could make valuable discoveries here.
Use as a gemstone
Amethyst gemstone quality is a popular and widespread jewelry stone which is ground to trade either in different faceted shapes ( diamond, marquise, Briolett ) or cabochon.
Be particularly valuable dark purple stones are. In addition, the varieties Ametrine (combination of amethyst and citrine in one stone) or the purple- banded white, opaque variety Amethystquarz are valued as a gemstone.
Manipulations, producing imitations and synthetics
Blowing of amethyst (approx. 400 ° C) produced the yellow to golden color of the variety citrine. Many of the misleadingly sold in the gem trade " of gold or Madeira topaz " is in fact burnt amethysts. Some amethysts burning produces similar to Prasiolith than what the fired Amethyst is then also sold a greenish hue. In the flame, but sometimes the color disappears completely and it is left white quartz.
Burnt stones usually get significantly more cracks and flaws that stand out for their luster. Often burst the crystal points and surfaces. In general, only amethysts are fired low quality to make it as " upgrade ". This is a copyrighted work, by which the color is changed using methods that seem identical in nature, while no significant properties are changed. Unfired Citrine is usually colored only light and has a matte always a mountain crystal-like long form. Citrine is no Druze, and is also a lot rarer than amethyst. Burnt -precious stones and gems do not have to be declared blown when a permanent color change is caused.
A cheap, but not very durable method to upgrade amethyst color, the treatment with colored wax, because unlike Agate Amethyst can stain only superficial.
Since the 20th century are mixes of various precious stones, as well as made the amethyst, which can be distinguished with gemological and mineralogical methods of investigation of natural amethysts, as they have over the naturally formed stone structure deviations.
For fashion jewelry amethyst is imitated by violet glass or offered in composite form as a duplicate.
Esoteric
Already Hildegard of Bingen (1098-1179) described in their "Book of the stones ," among other things the use of Amethyst as a healing stone against diseases such as blemishes and puffiness, but also against insects, spider and snake bites and lice.
In Esoterikerkreisen the Amethyst is also used as a healing stone in the gem therapy to support against alcoholism and other addictions. In addition it clean, inspiring and knowledge -generating properties are attributed by the influence on the brow chakra. Scientific evidence for such effects, however, do not exist yet, although periodic healing results have been recorded, but these are attributed to the placebo effect.
Amethyst are also often used for so-called "energetic cleaning " and " charge " of other healing stones used.
As a zodiac stone is the amethyst the zodiac sign fish, other sources say the star sign Sagittarius or Capricorn. As planetary stone he is associated with the planet Neptune or Pluto, and also stands for the month of February and the day Friday.