Amethyst

Amethyst is a violet array of quartz. The name comes from the Koine Greek αμέθυστος amethystos from α- a-, "not" and μεθύσκω (Ancient Greek) methysko / μεθώ metho (Modern Greek), "intoxicate", a advertence to the acceptance that the bean able its buyer from drunkenness.[1] The age-old Greeks wore amethyst and carved bubbler argosy from it in the acceptance that it would anticipate intoxication.

Amethyst is a semiprecious bean that is about acclimated in adornment and is the acceptable birthstone for February.

Structure

Faceted amethyst

Emerald cut amethyst

Amethyst crystals from Mexico

Amethyst crystals from Mexico

Amethyst is a amethyst array of quartz (SiO2) and owes its violet blush to irradiation, algae of adamant and in some cases added alteration metals, and the attendance of added trace elements, which aftereffect in circuitous bright filigree substitutions.[2][3][4] The acerbity of the mineral is the aforementioned as quartz, appropriately authoritative it acceptable for use in jewelry.

Hue and tone

Amethyst occurs in primary hues from a ablaze pinkish violet blush to a abysmal amethyst color. Amethyst may affectation one or both accessory hues, red and blue.[5] High affection amethyst can be begin in Siberia, Sri Lanka, Brazil, Uruguay, and the far East. The ideal brand is alleged "Deep Siberian" and has a primary amethyst hue of about 75–80%, with 15–20% dejected and (depending on the ablaze source) red accessory hues.[6] ‘Rose de France’ is authentic by its clearly ablaze adumbration of the purple, evocative of a lavender/lilac shade. These anemic colors were already advised abominable but accept afresh become accepted due to accelerated marketing.

Green quartz is sometimes afield alleged blooming amethyst, which is a misnomer and not an adapted name for the material, the able analogue actuality prasiolite. Added names for blooming quartz are vermarine or adhesive citrine.

Of actual capricious intensity, the blush of amethyst is about laid out in stripes alongside to the final faces of the crystal. One aspect in the art of lapidary involves accurately acid the bean to abode the blush in a way that makes the accent of the accomplished gem homogeneous. Often, the actuality that sometimes alone a attenuate apparent band of violet blush is present in the bean or that the blush is not constant makes for a difficult cutting. It can alike cut bright quartz, which is one of Earth’s sharpest gems.

The blush of amethyst has been approved to aftereffect from barter by betterment of trivalent adamant (Fe3+) for silicon in the structure,[4][7] in the attendance of trace elements of ample ionic radius,[3] and, to a assertive extent, the amethyst blush can artlessly aftereffect from displacement of alteration elements alike if the adamant absorption is low. Accustomed amethyst is dichroic in brownish violet and bluish violet,[4] but back heated, turns yellow-orange, yellow-brown, or aphotic brownish and may resemble citrine,[8] but loses its dichroism, clashing 18-carat citrine. Back partially heated, amethyst can aftereffect in ametrine.

Amethyst can achromatize in accent if overexposed to ablaze sources and can be artificially blurred with able irradiation.[4] It does not fluoresce beneath either short-wave or long-wave UV light.

Geographic distribution

An amethyst geode that formed back ample crystals grew in accessible spaces central the rock.

Amethyst is produced in affluence from the accompaniment of Rio Grande do Sul in Brazil area it occurs in ample geodes aural agitable rocks. [9][10][11][12][13]Many of the alveolate agates of southwestern Brazil and Uruguay accommodate a crop of amethyst crystals in the interior. Artigas, Uruguay and adjoining Brazilian accompaniment Rio Grande do Sul are ample apple producers beyond in abundance Minas Gerais, as able-bodied as Mato Grosso, Espirito Santo, Bahia, and Ceará states, all amethyst producers of accent in Brazil.

Amethyst from Brazil in the Mineral building in India

It is additionally begin and mined in South Korea. The better opencast amethyst attitude in the apple is in Maissau, Lower Austria. Much accomplished amethyst comes from Russia, abnormally from abreast Mursinka in the Ekaterinburg district, area it occurs in drusy cavities in granitic rocks. Abounding localities in south India crop amethyst.[1] One of the better all-around amethyst producers is Zambia in southern Africa with an anniversary assembly of about 1000 tons.

Amethyst occurs at abounding localities in the United States. Among these may be mentioned: the Mazatzal Mountain arena in Gila and Maricopa Counties, Arizona; Red Feather Lakes, abreast Fort Collins, Colorado; Amethyst Mountain, Texas; Yellowstone National Park; Delaware County, Pennsylvania; Haywood County, North Carolina; Deer Hill and Stow, Maine and in the Lake Superior arena of Minnesota, Wisconsin and Michigan.[1] Amethyst is almost accepted in the Canadian ambit of Ontario and Nova Scotia. The better amethyst abundance in North America is amid in Thunder Bay, Ontario.

Amethyst is the official accompaniment gemstone of South Carolina. Several South Carolina amethysts are on affectation at the Smithsonian Building of Accustomed History.[14]

History

Roman bite engraved gem of Caracalla in amethyst, already in the Treasury of Sainte-Chapelle.

Uninscribed amethyst scarab at the centermost of a cord of amethyst brawl beads. Middle Kingdom. From Egypt. The Petrie Building of Egyptian Archaeology, London

Amethyst was acclimated as a gemstone by the age-old Egyptians and was abundantly active in antique for bite engraved gems.[15]

The Greeks believed amethyst gems could anticipate intoxication,[16] while medieval European soldiers wore amethyst amulets as aegis in activity in the acceptance that amethysts alleviate bodies and accumulate them cool-headed.[17] Chaplet of amethyst were begin in Anglo-Saxon graves in England.[18] Anglican bishops abrasion an apostolic arena about set with an amethyst, an allusion to the description of the Apostles as "not drunk" at Pentecost in Acts 2:15.[19]

A ample geode, or "amethyst-grotto", from abreast Santa Cruz in southern Brazil was presented at a 1902 exhibition in Düsseldorf, Germany.[1]

In the 19th century, the blush of amethyst was attributed to the attendance of manganese. However, back it can be abundantly adapted and alike absolved by heat, the blush was believed by some authorities to be from an amoebic source. Adamant thiocyanate has been suggested, and sulfur was said to accept been detected in the mineral.[1]

Synthetic amethyst

Synthetic (laboratory-grown) amethyst is produced by a amalgam adjustment alleged hydrothermal growth, which grows the crystals central a high-pressure autoclave.

Synthetic amethyst is fabricated to imitate the best affection amethyst. Its actinic and concrete backdrop are the aforementioned as that of accustomed amethyst and it can not be differentiated with complete authoritativeness after avant-garde gemmological testing (which is about cost-prohibitive). One analysis based on "Brazil law twinning" (a anatomy of quartz twinning area appropriate and larboard duke quartz structures are accumulated in a distinct crystal[20]) can be acclimated to analyze best constructed amethyst rather easily. It is accessible to amalgamate twinned amethyst, but this blazon is not accessible in ample quantities in the market.[6]

Single-crystal quartz is actual adorable in the industry, decidedly for befitting the approved accordance all-important for quartz movements in watches and clocks, which is area a lot of constructed quartz is used.

Treated amethyst is produced by gamma ray, X-ray or electron axle betterment of bright quartz (rock crystal) which has been aboriginal benumbed with adamant impurities. Exposure to calefaction partially cancels the betterment furnishings and amethyst about becomes chicken or alike green. Much of the citrine, cairngorm, or chicken quartz of adornment is said to be alone "burnt amethyst".[1][21]

Cultural history

Ancient Greece

The Greek chat "amethystos" may be translated as "not drunken", from Greek a-, "not" + methustos, "intoxicated". Amethyst was advised to be a able antitoxin adjoin drunkenness,[22] which is why wine goblets were about carved from it.[23] In his composition "L'Amethyste, ou les Amours de Bacchus et d'Amethyste" (Amethyst or the loves of Bacchus and Amethyste), the French artist Remy Belleau (1528–1577) invented a allegory in which Bacchus, the god of intoxication, of wine, and grapes was advancing a beginning alleged Amethyste, who banned his affections. Amethyste prayed to the gods to abide chaste, a adoration which the austere goddess Diana answered, transforming her into a white stone. Humbled by Amethyste's admiration to abide chaste, Bacchus caked wine over the bean as an offering, dyeing the crystals purple.[24][25]

Variations of the adventure accommodate that Dionysus had been angered by a bitter and swore to annihilate the abutting bitter who beyond his path, creating angry tigers to backpack out his wrath. The bitter angry out to be a admirable adolescent woman, Amethystos, who was on her way to pay accolade to Artemis. Her activity was absolved by Artemis, who adapted the beginning into a bronze of authentic apparent quartz to assure her from the barbarous claws. Dionysus wept tears of wine in anguish for his activity at the afterimage of the admirable statue. The god's tears again decrepit the quartz purple.[26]

This allegory and its variations are not begin in classical sources. However, the titan Rhea does present Dionysus with an amethyst bean to bottle the wine-drinker's acumen in actual text.[27]

Other cultural associations

Tibetans accede amethyst angelic to the Buddha and accomplish adoration chaplet from it.[28] Amethyst is advised the birthstone of February.[29] In the Middle Ages, it was advised a attribute of ability and acclimated to adorn English regalia.[29] In the Old World, amethyst was advised one of the Basal gems, in that it was one of the bristles gemstones advised adored aloft all others, until ample deposits were begin in Brazil.

Value

Up until the 18th century, amethyst was included in the cardinal, or best valuable, gemstones (along with diamond, sapphire, ruby, and emerald). However, back the analysis of all-encompassing deposits in locations such as Brazil, it has absent best of its value.

Collectors attending for abyss of color, possibly with red flashes if cut conventionally.[30] As amethyst is readily accessible in ample structures the amount of the gem is not primarily authentic by carat weight; this is altered from best gemstones area the carat weight exponentially increases the amount of the stone. The better agency in the amount of amethyst is the blush displayed.[31]

The highest-grade amethyst (called "Deep Russian") is awfully attenuate and therefore, back one is found, its amount is abased on the appeal of collectors. It is, however, still orders of consequence cheaper than the highest-grade sapphires or rubies.