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Amethyst
General
Category Mineral variety
Chemical formula Silica (silicon dioxide, SiO2)
Identification
Color Violet
Crystal habit 6-sided prism ending in 6-sided pyramid (typical)
Crystal system rhombohedral class 32
Twinning Dauphine law, Brazil law, and Japan law
Cleavage None
Fracture Conchoidal
Mohs scale hardness 7–lower in impure varieties
Luster Vitreous/glossy
Streak White
Diaphaneity Transparent to translucent
Specific gravity 2.65 constant; variable in impure varieties
Optical properties Uniaxial (+) (Positive)
Refractive index nω = 1.543–1.553 nε = 1.552–1.554
Birefringence +0.009 (B-G interval)
Pleochroism None
Melting point 1650±75 °C
Solubility H2O insoluble
Other characteristics Piezoelectric

Amethyst is a violet variety of quartz often used in jewelry. The name comes from the Ancient Greek a- ("not") and μέθυστος methustos ("intoxicated"), a reference to the belief that the stone protected its owner from drunkenness; the ancient Greeks and Romans wore amethyst and made drinking vessels of it in the belief that it would prevent intoxication.

Contents

Chemistry

Amethyst is the violet variety of quartz; its chemical formula is SiO2.

In the 20th century, the color of amethyst was attributed to the presence of manganese. However, since it is capable of being greatly altered and even discharged by heat, the color was believed by some authorities to be from an organic source. Ferric thiocyanate was suggested, and sulfur was said to have been detected in the mineral.

More recent work has shown that amethyst's coloration is due to ferric iron impurities.[1] Further study has shown a complex interplay of iron and aluminium is responsible for the color.[2]

On exposure to heat, amethyst generally becomes yellow, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely "burnt amethyst". Veins of amethystine quartz are apt to lose their color on the exposed outcrop[citation needed].

Synthetic amethyst is made to imitate the best quality amethyst. Its chemical and physical properties are so similar to that of natural amethyst that it can not be differentiated with absolute certainty without advanced gemological testing (which is often cost-prohibitive). There is one test based on "Brazil law twinning" (a form of quartz twinning where right and left hand quartz structures are combined in a single crystal[3]) which can be used to identify synthetic amethyst rather easily. In theory however it is possible to create this material synthetically as well, but this type is not available in large quantities in the market.[4]

Composition

Amethyst is composed of an irregular superposition of alternate lamellae of right-handed and left-handed quartz. It has been shown that this structure may be due to mechanical stresses.

Because it has a hardness of seven on the Mohs scale, amethyst is suitable for use in jewelry.

Hue and tone

Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80 percent, 15–20 percent blue and (depending on the light source) red secondary hues.[4] Green Quartz is sometimes called green amethyst. Other names for green quartz are Prasiolite,Vermarine or Lime Citrine.

History

Roman intaglio engraved gem of Caracalla in amethyst, once in the Treasury of Sainte-Chapelle.

Amethyst was used as a gemstone by the ancient Egyptians and was largely employed in antiquity for intaglio engraved gems. [5]

The Greeks believed amethyst gems could prevent intoxication, while medieval European soldiers wore amethyst amulets as protection in battle. The reason for this being that amethysts are believed to heal people and keep them cool-headed. [6] Beads of amethyst were found in Anglo-Saxon graves in England.[citation needed]

A huge geode, or "amethyst-grotto", from near Santa Cruz in southern Brazil was exhibited at the Düsseldorf, Germany Exhibition of 1902.

Amethyst is the traditional birthstone for February.

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Mythology

The Greek word "amethystos" may be translated as "not drunken", from Greek a-, not + methustos, intoxicated[7]. Amethyst was considered to be a strong antidote against drunkenness, which is why wine goblets were often carved from it. In Greek mythology, Dionysus, the god of intoxication,and wine, was pursuing a maiden named Amethystos, who refused his affections. Amethystos prayed to the gods to remain chaste, which the goddess Artemis granted and transformed her into a white stone. Humbled by Amethystos's desire to remain chaste, Dionysus poured wine over the stone as an offering, dyeing the crystals purple.

Variations of the story include that Dionysus had been insulted by a mortal and swore to slay the next mortal who crossed his path, creating fierce tigers to carry out his wrath. The mortal turned out to be a beautiful young woman, Amethystos, who was on her way to pay tribute to Artemis(the hunter goddess). Her life is spared by Artemis, who transformed the maiden into a statue of pure crystalline quartz to protect her from the brutal claws. Dionysus wept tears of wine in remorse for his action at the sight of the beautiful statue. The god's tears then stained the quartz purple.[8] Another variation involves the titan Rhea presenting Dionysus with the amethyst stone to preserve the wine-drinker's sanity.[9]

Geographic distribution

Amethyst is produced in abundance from the state of Minas Gerais in Brazil where it occurs in large geodes within volcanic rocks. It is also found and mined in South Korea. The largest opencast amethyst vein in the world is in Maissau, Lower Austria. Many of the hollow agates of Brazil and Uruguay contain a crop of amethyst crystals in the interior. Much fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities in granitic rocks. Many localities in India yield amethyst. One of the largest global amethyst producers is Zambia with an annual production of about 1,000 t.

Amethyst cluster

Amethyst occurs at many localities in the United States. Among these may be mentioned: the Mazatzal Mountain region in Gila and Maricopa Counties, Arizona; Amethyst Mountain, Texas; Yellowstone National Park; Delaware County, Pennsylvania; Haywood County, North Carolina; Deer Hill and Stow, Maine and in the Lake Superior region. Amethyst is relatively common in Ontario, and in various locations throughout Nova Scotia. The largest amethyst mine in North America is located in Thunder Bay, Ontario.[10] .

Value

Up to 18th century amethyst was included in the cardinal, or most valuable, gemstones (along with diamond, sapphire, ruby, and emerald). However since the discovery of extensive deposits in locations such as Brazil it has lost most of its value.

Collectors look for depth of color, possibly with red flashes if cut conventionally. [11]. The highest grade amethyst (called "Deep Russian") is exceptionally rare and therefore its value is dependent on the demand of collectors when one is found. It is however still orders of magnitude lower than the highest grade sapphires or rubies (Padparadscha sapphire or "pigeon's blood" ruby).[4]

See also

Notes

  1. ^ Klein, Cornelis and Hurlbut, Cornelius S., 1985 Manual of Mineralogy (after JD Dana) 20th edition, p. 441, John Wiley & Sons, New York
  2. ^ Cohen, Alvin J., 1985, Amethyst color in quartz, the result of radiation protection involving iron', American Mineralogist, V. 70, pp 1180-1185
  3. ^ "Quartz Page Twinning Crystals". http://quartzpage.de/crs_twins.html. Retrieved 2007-05-28. 
  4. ^ a b c Secrets of the Gem Trade; The Connoisseur's Guide to Precious Gemstones Richard W Wise, Brunswick House Press, Lenox, Massachutes., 2003
  5. ^ Gems, Notes and Extracts Augosto Castellani (famous Italian 19th century jeweler), page 34, London, Bell&Daldy, 1871
  6. ^ Diamonds, Pearls and Precious Stones Marcell N Smith, Griffith Stillings Press, Boston, Massachutes., 1913, page 74
  7. ^ The American Heritage Dictionary
  8. ^ http://gemstone.org/gem-by-gem/english/amethyst.html source
  9. ^ (Nonnus, Dionysiaca, XII.380)
  10. ^ Amethyst Mine http://amethystmine.com/history.html
  11. ^ CIBJO guidelines,

References

  • "Amethyst". part of a poster by the Juneau – John Rishel Mineral Information Center. Alaska office of the United States Bureau of Land Management. http://www.blm.gov/ak/jrmic/poster/amethyst.html. Retrieved 2006-09-11. 
  • Ure, Andrew (1827). A Dictionary of Chemistry. Printed for Thomas Tegg, (et al.). p. 141. http://books.google.com/books?vid=OCLC22415868&id=9YS0XNQU8x4C&pg=PA141&lpg=PA141&dq=Amethyst&as_brr=1. Retrieved 2006-09-11. "The amethyst is a gem of a violet colour, and great brilliancy, said to be as hard as the ruby or sapphire, from which it only differs in colour. This is called the oriental amethyst, and is very rare. When it inclines to the purple or rosy colour, it is more esteemed than when it is nearer to the blue. These amethysts have the same figure, hardness, specific gravity, and other qualities, as the best sapphires or rubies, and come from the same places, particularly from Persia, Arabia, Armenia and the West Indies. The occidental amethysts are merely coloured crystal or quartz." 

External links

This article incorporates text from the Encyclopædia Britannica, Eleventh Edition, a publication now in the public domain.


1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

AMETHYST, a violet or purple variety of quartz used as an ornamental stone. The name is generally said to be derived from the Gr. not,"and /2E0150-KELv, to intoxicate," expressing the old belief that the stone protected its owner from strong drink. It was held that wine drunk out of a cup of amethyst would not intoxicate. According, however, to the Rev. C. W. King, the word may probably be a corruption of an Eastern name for the stone.

The colour of amethyst is usually attributed to the presence of manganese, but as it is capable of being much altered and even discharged by heat it has been referred by some authorities to an organic source. Ferric thiocyanate has been suggested, and sulphur is said to have been detected in the mineral. On exposure to heat, amethyst generally becomes yellow, and much of the cairngorm or yellow quartz of jewellery is said to be merely "burnt amethyst." Veins of amethystine quartz are apt to lose their colour on the exposed outcrop.

Amethyst is composed of an irregular superposition of alternate lamellae of right-handed and left-handed quartz. (See Quartz.) It has been shown by Prof. J. W. Judd that this structure may be due to mechanical stresses. In consequence of this composite formation, amethyst is apt to break with a rippled fracture, or to show "thumb markings," and the intersection of two sets of curved ripples may produce on the fractured surface a pattern something like that of "engine turning." Some mineralogists, following Sir D. Brewster, apply the name of amethyst to all quartz which exhibits this structure, regardless of its colour.

The amethyst was used as a gem-stone by the ancient Egyptians, and was largely employed in antiquity for intaglios. Beads of amethyst are found in Anglo-Saxon graves in England. Amethyst is a very widely distributed mineral, but fine clear � specimens fit for cutting as ornamental stones are confined to comparatively few localities. Such crystals occur either in cavities in mineral-veins and in granitic rocks, or as a lining in agate geodes. A huge geode, or "amethyst-grotto," from near Santa Cruz in southern Brazil, was exhibited at the Dusseldorf Exhibition of 1902. Many of the hollow agates of Brazil and Uruguay contain a crop of amethyst-crystals in the interior. Much fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities in granitic rocks. Many localities in India yield amethyst; and it is found also in Ceylon, chiefly as pebbles.

Purple corundum, or sapphire of amethystine tint, is called Oriental amethyst, but this expression is often applied by jewellers to fine examples of the ordinary amethystine quartz, even when not derived from Eastern sources.

Amethyst occurs at many localities in the United States, but rarely fine enough for use in jewellery. Among these may be mentioned Amethyst Mountain, Texas; Yellowstone National Park; Delaware Co., Pennsylvania; Haywood Co., North Carolina; Deer Hill, and Stow, Maine. It is found also in the Lake Superior district. See G. F. Kunz, Gems &c. of North America (1890), and Report for.2th Census (vol. "Mines and Quarries"). (F.W.R.*)


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Wiktionary

Up to date as of January 15, 2010

Definition from Wiktionary, a free dictionary

See also amethyst

German

Noun

Amethyst m. (genitive Amethysts or Amethystes, plural Amethyste)

  1. amethyst

Bible wiki

Up to date as of January 23, 2010

From BibleWiki

One of the precious stones in the breastplate of the high priest (Ex 28:19; Ex 39:12), and in the foundation of the New Jerusalem (Rev 21:20). The ancients thought that this stone had the power of dispelling drunkenness in all who wore or touched it, and hence its Greek name formed from a_, "privative," and _methuo, "to get drunk." Its Jewish name, ahlamah', was derived by the rabbins from the Hebrew word halam, "to dream," from its supposed power of causing the wearer to dream.

It is a pale-blue crystallized quartz, varying to a dark purple blue. It is found in Persia and India, also in different parts of Europe.

This entry includes text from Easton's Bible Dictionary, 1897.

what mentions this? (please help by turning references to this page into wiki links)

This article needs to be merged with AMETHYST (Jewish Encyclopedia).

Simple English

File:Amethyst by
Amethyst crystals.

An amethyst is a sometimes transparent mineral that comes from quartz. It is a type of rock. It is valued because of its violet colour. Even though it is from quartz, it has more iron oxide (Fe2O3) than any other kind of quartz.[1] Because of this, some experts think that its colour comes from the iron in it.[1] Heating the amethyst either takes away its colour or changes it to a yellow color. Amethysts are found in Brazil, Uruguay, Ontario, and North Carolina. The rock amethyst is the birthstone of the month February.

Contents

Meaning and superstition

Many people believe amethysts protect one from poison, evil, and getting drunk.[2] This is where the name of this rock came from, the Greek word amethustos, meaning "without being drunken". Also they are thought to be good for hearing, recovering from headaches, good dreams, and more. Some catholic popes also wear it around their necks. [3] Also, some roman women thought gems could keep their husbands faithful to them.

Amethysts are also worn because people think it makes them look gentle.[3] The “powers” in the amethyst also includes healing, peace, love, more spirituality, courage, protection from robbers, and happiness.[3]

In the Mohs scale, it is included as the number seven.[3]

In religion

The amethyst is very famous for being one of the main gemstones of Christianity and Catholicism.[4] Some catholic popes wear amethysts around their necks because they think it makes them look pious and more holy. Also in christianity, the Bible says about a breastplate decorated with jewels worn by Aaron, the most high priest of the Hebrews. It had 12 jewels on it, and the amethyst was the third stone in the third row. In the New Testament, according to the Bible, the amethyst became the foundation of the Jerusalem. This description came out in Book of Revelations. Each gemstone was a symbol of something. The amethyst stood for being a gift of tongues and was filled with the desire to please God.[4]

Decoration

The amethyst is worn and used for fashion in a number of different ways. It is polished and shaped for rings, earrings, and cuff links. It may be also used for brooches, sometimes being carved into a cluster of grapes. People like the way amethysts look especially when they are put in gold and diamonds.[4]

History

In the legends, there are many stories about amethysts. One of them claim how amethysts were legendarily created. According to the story, Bacchus, the Roman god of wine and conviviality, was angry because of something against him and wanted to revenge.[4] He ordered that the first person who was mortal to come across his path would be eaten by tigers. Just at that moment a beautiful maiden named Amethyst came, on her way to worship the goddess Diana. Diana saw what was going to happen and she quickly made Amethyst a stone to save her from the tigers. When Bacchus saw this, he repented and poured wine over the stone, making its color purple.[4]

Royalty

The amethyst is worn a lot by kings and queens, and high people. This is because its royal color was purple. When it was found in the Minoan period in Greece (c. 2500 B.C.), it was polished and shaped like cabochons (dome-shaped stones). Then, it was set in gold. During the 15th century, the French fleur-de-lis brooch could only be worn by the Royal family on special times.[4] The fleur-de-lis design on it is put in with sapphires and amethysts.[5]

Other pages

References


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