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Here I have collected some information about gemstones Lapis Lazuli - looked at some of the markets in Mahmutlar in Alanya, Turkey.

Lapis Lazuli


Lapis
Lazuli has been a treasured stone since ancient times, sacred to the Egyptian, Babylonians, Sumerians and most ancient civilizations. Lapis Lazuli's name is derived from Persian Lazhuward for Blue and Arabic Lazaward for heaven or sky. Lapis is not actually a gem, but a composite rock comprising of mainly Lazurite (25-40 percent) and pyrite, calcite, sodalite, hauyne, mica, enstatie, diopside, hornblende, and/or nosean. The coloring agent is sulfur. The finest color Lapis has a deep even blue color that has a purplish tint or tone and is free of any inclusions. I personally disagree, I love the pyrite inclusions that give the stone the appearance of a night sky with stars. Lapis has a hardness of 5-6 and is sensitive to heat and pressure.

Denim Lapis

Denim Lapis is lapis that is heavily included with calcite giving it a denim appearance.

Fakes and Treatments

Gilson Lapis

Synthetic Lapis made by Pierre Gilson of France, it is much softer and impractical to use

Synthetic Lapis

First manufactured in the 50s, it consists of grainy blue spinel colored by cobalt oxide and gold flakes to resemble pyrite. The material is much harder, which makes it easier to distinguish

Reconstructed Lapis

Tiny chips of lapis and pyrite cemented together the same way reconstructed turquoise is made.

Dyed Lapis

A good quality of lesser quality lapis is dyed to improve the blue tone, once the stone is dyed it is often oiled or waxed to improve luster

Dyed Howlite

White howlite is dyed to create a lapis substitute, the dye tends to fade and there is no pyrite inclusions.

Mountain Jade Lapis

This stone is not Jade or Lapis, but a dolomite marble dyed bright blue! Another stone that the color fades and there is no inclusions of pyrite

German Lapis

Also called Swiss Lapis, a blue dyed jasper that is also lacking in pyrite inclusions

Misidentification

Sodalite

sodalite is one of the components that makes up Lapis, but the stone itself is actually more indigo then lapis and lacks the pyrite. Another way to tell the difference is a streak test, Lapis has a light blue streak while sodalite has a white streak

Azurite

Azurite usually forms crusts along side malachite, but when it forms crystals it can me unbelievable! The color is much darker, so deep that it is almost black. Azurite is also much softer then Lapis, only a 3.5-4 on the scale.

Dumortierite

Dumortierite is a darker indigo than Lapis, and also lacks the pyrite inclusions.

Lapis Lazuli from Afghanistan

Sar-e-Sang Mine, Jurm, Afghanistan

Royal blue lapis lazuli, the gem variety of lazurite and one of the most beautiful opaque gemstones, is a sodium and aluminum mineral of considerable complexity. Known as “sapphires” by the ancients, the stone occurs in only a few major deposits around the world, notably Lake Baikal in Siberia, Ocalle
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter BancroftThe ancient royal Sumerian tombs of Ur, located near the Euphrates River in lower Iraq, contained more than 6000 beautifully executed lapis lazuli statuettes of birds, deer, and rodents as well as dishes, beads, and cylinder seals. These carved artifacts undoubtedly came from material mined in northern Afghanistan. Later Egyptian burial sites dating before 3000 B.C. contained thousands of jewelry items, many of lapis. Powdered lapis was favored by Egyptian ladies as a cosmetic eye shadow and in later years it was used as a pigment for ultramarine paints. Pliny the Elder described the stone as “a fragment of the starry firmament.”
The most prized lapis is a dark, nearly blackish blue, much deeper than turquoise and more intense than sodalite or azurite. Lazurite occurs most frequently in lighter shades commonly mixed with streaks of calcite. Although attractive, this material is less desirable and consequently fetches a lower price. Pyrite, a commonly associated mineral, is often liberally sprinkled throughout lapis specimens, to create a striking combination of rich blue and brassy gold.

Lapis lazuli
Size: 9 by 6 cm
Locality: Sar-e-Sang
Collection: Private collection
Photo: Harold and Erica Van Pelt
lapis lazuli, Afghan lapis, lapis, sar-e-sang, Peter Bancroft, gem & crystal treasures

The route to the lapis mines in the Kokcha Valley is long, tortuous, and dangerous. From Feysbad, capital of Afghanistan’s northeast province of Badakhshan, a poor road stretches southward through tiny hamlets of mud-walled huts standing on uneven ground wracked by the earthquake of 1832. After motoring as far as Hazarat-Said, the traveler must spend another full day on horseback before reaching Kokcha Valley. The small Kokcha River is the eastern tributary of the River Oxus which Marco Polo traversed and wrote: “There is a mountain in that region where the finest azure [lapis lazuli] in the world is found. It appears in veins like silver streaks.”

Map of Afghanistan showing the location of the lapis lazuli mines. (Illustration ©Richard Hughes)
   The lapis is mined on the steep sides of a long narrow defile sometimes only 200 meters wide and backed by jagged peaks that rise above 6000 meters. Sparsely populated and covered with snow for much of the year the barren region is inhabited by wild hogs and wolves. The summer sun is scorching, but temperatures drop below freezing at night. British Army Lieutenant John Wood reached the lapis mines for the East India Company in 1837, and wrote in his Journey to the Source of the River Oxus, “If you do not wish to die, avoid the Valley of Kokcha.” This is surely not one of the world’s better sites for a field trip!
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
Pack train in high, desolate and very cold Kokcha Valley.
Darreh-Zu, one of the oldest mines along the Kokcha, is now closed and presumably exhausted. The nearby and relatively new Sar-e-Sang mine currently yields substantial amounts of good quality gem material and has produced rare 5-centimeter lazurite crystals. The largest found thus far, a well formed dodecahedron imbedded in calcite, was collected in 1964 by Pierre Bariand, mineral collection curator at The Sorbonne.
Lazurite gem deposits occur in white and black marbles hundreds of meters thick. The gem veins, seldom exceeding 10 meters in length, lie in snow-white calcite. Associated minerals include pyrite, diopside, sodalite, forsterite, phlogopite, garnet, dolomite, apatite, and afghanite, a relatively new species of the cancrinite group. Gem lazurite is found in three Persian color classifications: nili (dark blue), assemani (light blue), and sabz (green).
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
The Sar-e-Sang is high on a cliff but has produced the largest lapis lazuli crystals of all time.
During the 1880s and early 1900s, lazurite was mined by the “fire-set” method: large fires were kindled at the tunnel face and then quenched with water. The sudden cooling caused face rocks to shatter, simplifying removal of the ore. The gem material was then cobbed away from its matrix. A critical shortage of wood and the availability of explosives eventually rendered the technique obsolete.
Many leading museums feature carvings and jewelry fashioned from Kokcha lapis. But nowhere is the gem more lavishly displayed than in Leningrad’s Hermitage Museum, where deep-blue figurines and vases stand 2 meters high.
The Sar-e-Sang mine has reserves of high-grade lapis lazuli and possibly more of the very rare lapis crystals. But political instability in Afghanistan clouds the future for both mining and distribution of the noble blue gem.
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
Lazurite crystal in marble.
Size of crystal: 5 cm; Locality: Sar-e-Sang.

 

Introduction. Lapis lazuli is one of the oldest of all gems, with a history stretching back some 7000 years or more. This mineral is important not just as a gem, but also as a pigment, for ultramarine is produced from crushed lapis lazuli (this is why old paintings using ultramarine for their blue pigments never fade).

Color. For lapis lazuli, the finest color will be an even, intense blue, lightly dusted with small flecks of golden pyrite. There should be no white calcite veins visible to the naked eye and the pyrite should be small in size. This is because the inclusion of pyrite often produces discoloration at the edges which is not so attractive. Stones which contain too much calcite or pyrite are not as valuable.

Clarity. Lapis lazuli is essentially opaque to the naked eye. However, fine stones should possess no cracks which might lower durability.

Cut. Lapis lazuli is cut similar to other ornamental stones. Cabochons are common, as are flat polished slabs and beads. Carvings and figurines are also common.

Prices. Lapis lazuli is not an expensive stone, but truly fine material is still rare. Lower grades may sell for less than $1 per carat, while the superfine material may reach $100–150/ct. or more at retail.

Stone Sizes. Lapis lazuli may occur in multi-kilogram sized pieces, but top-grade lapis of even 10–20 carats cut is rare.

Name. The name lapis means stone. Lazuli is derived from the Persian lazhward, meaning blue. This is also the root of our word, azure.

Sources. The original locality for lapis lazuli is the Sar-e-Sang deposit in Afghanistan’s remote Badakhshan district. This mine is one of the oldest in the world, producing continuously for over 7000 years. While other deposits of lapis are known, none are of importance when compared with Afghanistan. Lapis lazuli is also found in Chile, where the material is heavily mottled with calcite. Small amounts are also mined in Colorado, near Lake Baikal in Siberia, and in Burma’s Mogok Stone Tract.

Enhancements. The most common enhancement for lapis lazuli is dying (staining), where a stone with white calcite inclusions is stained blue to improve the color. Other enhancements commonly seen are waxing and resin impregnations, again, to improve color. The color of stained lapis is unstable and will fade with time. As with all precious stones, it is a good practice to have any major purchases tested by a reputable gem lab, to determine if a gem is enhanced.

Imitations. Sintered synthetic blue spinel was once used as an imitation of lapis lazuli, but is rarely seen today. So-called synthetic lapis lazuli (such as the Gilson product) is more properly termed an imitation, since it does not match exactly the structure and properties of the natural. It is found in various forms, complete with pyrite specks (but all lacking calcite). Various forms of glass and plastic are also commonly seen as lapis imitations.

lapis lazuli ring
The above stone is an example of why Afghan lapis lazuli is in a league all its own. Jewelry: The Collector;

Properties of Lapis Lazuli

Composition Rock made primarily of lazurite (Na, Ca)8(Al, Si)12O24(S, SO4). Also contains haüyne, sodalite and nosean, which are all members of the sodalite group.
Hardness (Mohs) Variable. Generally 5–6
Specific Gravity Variable. Generally 2.7–2.9
Refractive Index ca. 1.50
Crystal System None (lapis is a rock). Lazurite, the main constituent, is isometric, and frequently occurs as dodecahedra.
Colors

Blue, mottled with white calcite and brassy pyrite

Pleochroism None
Phenomena None
Handling Due to its softness, care must be taken in the wearing of lapis lazuli.
  Frequently dyed or impregnated
Synthetic available? Yes

From Wikipedia, the free encyclopedia

Lapis lazuli

A polished specimen of lapis lazuli.
General
Category Rock
Chemical formula mixture of minerals
Identification
Color Blue, mottled with white calcite and brassy pyrite
Crystal habit Compact, massive
Crystal system None, as lapis is a rock. Lazurite, the main constituent, frequently occurs as dodecahedra
Cleavage None
Fracture Uneven-Conchoidal
Luster dull
Streak light blue
Specific gravity 2.7-2.9
Refractive index 1.5
Other characteristics The variations in composition cause a wide variation in the above values.

Lapis lazuli (pronounced /ˈlæpɪs ˈlæz(j)ʊlaɪ/ or /ˈlæzjʊli/ LAP-iss LAZ-yu-lye/lee[1]) (sometimes abbreviated to lapis) is a relatively rare, semi-precious stone that has been prized since antiquity for its intense blue color.

Lapis lazuli has been mined in the Badakhshan province of Afghanistan for over 6,000 years, and trade in the stone is ancient enough for lapis jewelry to have been found at Predynastic Egyptian sites, and lapis beads at neolithic burials in Mehrgarh, the Caucasus, and even as far from Afghanistan as Mauritania.[2]

 

Description

Rough and polished Lapis lazuli.

Lapis lazuli is a rock, not a mineral: whereas a mineral has only one constituent, lapis lazuli is formed from more than one mineral.[3]

The main component of lapis lazuli is lazurite (25% to 40%), a feldspathoid silicate mineral composed of sodium, aluminium, silicon, oxygen, sulfur, and chloride. Its formula is (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2.[4] Most lapis lazuli also contains calcite (white), sodalite (blue), and pyrite (metallic yellow). Other possible constituents are augite, diopside, enstatite, mica, hauynite, hornblende, and nosean. Some contain trace amounts of the sulfur rich lollingite variety geyerite.

Lapis lazuli usually occurs in crystalline marble as a result of contact metamorphism.

The finest color is intense blue, lightly dusted with small flecks of golden pyrite. Stones with no white calcite veins and only small pyrite inclusions are more prized. Patches of pyrite are an important help in identifying the stone as genuine and do not detract from its value. Often, inferior lapis is dyed to improve its color, producing a very dark blue with a noticeable grey cast which may also appear as a milky shade.

Uses

Lapis takes an excellent polish and can be made into jewelry, carvings, boxes, mosaics, ornaments, and vases. In architecture it has been used for cladding the walls and columns of palaces and churches.

It was also ground and processed to make the pigment ultramarine for tempera paint and, more rarely, oil paint. Its usage as a pigment in oil paint ended in the early 19th century as a chemically identical synthetic variety, often called French Ultramarine, became available.

Etymology

Lapis is the Latin for 'stone' and lazuli the genitive form of the Medieval Latin lazulum, which is from the Arabic lāzaward, which is ultimately from the Persian لاژورد lāzhvard, the name of a place where lapis lazuli was mined.[5][6] The name of the place came to be associated with the stone mined there and, eventually, with its color. The English word azure, the French azur, the Spanish and Portuguese azul, and the Italian azzurro are cognates. Taken as a whole, lapis lazuli means 'stone of Lāzhvard'.

Sources

The best lapis lazuli is found in limestone in the Kokcha River valley of Badakhshan province in northeastern Afghanistan, and these deposits in the mines of Sar-e-Sang have been worked for more than 6,000 years.[7] Afghanistan was the source of lapis for the ancient Egyptian and Mesopotamian civilizations, as well as the later Greek and Roman; during the height of the Indus valley civilization about 2000 B.C., the Harappan colony now known as Shortugai was established near the lapis mines.[2]

In addition to the Afghan deposits, lapis has been extracted for years in the Andes near Ovalle, Chile, where the deep blue stones compete in quality with those from Afghanistan. Other less important sources include the Lake Baikal region of Russia, Siberia, Angola, Burma, Pakistan, USA (California and Colorado), Canada, and India.

Cultural and historical/mythical usage

A Mesopotamian lapis lazuli pendant circa 2900 BCE.
A 11 cm (4.3 in) long lapis lazuli dove studded with gold pegs. Elamite. Dated 1200BCE from Susa, Iran.
An Elephant carving in high quality lapis lazuli, showing gold-colored inclusions of pyrite. The carving is 8 cm (3.1 in) long.
Carved lapis lazuli of a mountain scene, from the Chinese Qing Dynasty (1644–1912).

In ancient Egypt lapis lazuli was a favorite stone for amulets and ornaments such as scarabs; it was also used by the Assyrians and Babylonians for seals. Lapis jewelry has been found at excavations of the Predynastic Egyptian site Naqada (3300–3100 BC), and powdered lapis was used as eyeshadow by Cleopatra.[2]

As inscribed in the 140th chapter of the Egyptian Book of the Dead, lapis lazuli, in the shape of an eye set in gold, was considered an amulet of great power. On the last day of the month, an offering was made before this symbolic eye, for it was believed that, on that day, the supreme being placed such an image on his head.[citation needed]

The ancient royal Sumerian tombs of Ur, located near the Euphrates River in lower Iraq, contained more than 6000 beautifully executed lapis lazuli statuettes of birds, deer, and rodents as well as dishes, beads, and cylinder seals. These carved artifacts undoubtedly came from material mined in Badakhshan in northern Afghanistan. Much Sumerian and Akkadian poetry makes reference to lapis lazuli as a gem befitting royal splendor.[citation needed]

In ancient times, lapis lazuli was known as sapphire,[8] which is the name that is used today for the blue corundum variety sapphire. It appears to have been the sapphire of ancient writers because Pliny refers to sapphirus as a stone sprinkled with specks of gold. A similar reference can be found in the Hebrew Bible in Job 28:6. The Bible (New Living Translation) also mentions lapis lazuli in Exodus 24:10 where God Himself seems to be standing upon it while on Mount Sinai.

Many of the blues in painting from medieval Illuminated manuscripts to Renaissance panels were derived from lapis lazuli. Ground to a powder and processed to remove impurities and isolate the component lazurite, it forms the pigment ultramarine. This clear, bright blue, which was one of the few available to painters before the 19th century, cost a princely sum. As tempera painting was superseded by the advent of oil paint in the Renaissance, painters found that the brilliance of ultramarine was greatly diminished when it was ground in oil and this, along with its cost, led to a steady decline in usage. Since the synthetic version of ultramarine was discovered in the 19th century (along with other 19th century blues, such as cobalt blue), production and use of the natural variety has almost ceased, though several pigment companies still produce it and some painters are still attracted to its brilliance and its romantic history.

Her har jeg samlet en rækker oplysninger om Smykkestenen Lapis Lazuli - set på nogle af markederne i Mahmutlar ved Alanya, Tyrkiet.

Lapis Lazuli


Lapis Lazuli har været en skattet sten siden oldtiden, hellig til den egyptiske, babylonierne, Sumererne og de ældste civilisationer. Lapis lazuli navn er afledt af persisk Lazhuward for blå og arabisk Lazaward til himlen eller luftrum. Lapis er faktisk ikke en perle, men en sammensat rock bestående af hovedsageligLazurite (25-40 procent) og svovlkis, calcit, sodalit, hauyne, glimmer, enstatie, diopside, hornblende, og / eller nosean. Farven agent er svovl. Den fineste farve Lapis har en dyb selv blå farve, der har en purpurrød farve eller tone og er fri for indeslutninger. Jeg personligt er uenig, jeg elsker svovlkis optagelser, der giver stenen fremkomsten af en nattehimmel med stjerner. Lapis har en hårdhed på 5-6 og er følsom over for varme og tryk. 


Denim Lapis

Denim Lapis er lapis, der er stærkt medtaget med calcit give den et denim udseende.

Forfalskninger og behandlinger

Gilson Lapis

Syntetisk Lapis lavet af Pierre Gilson i Frankrig, det er meget blødere og upraktisk at bruge 

Synthetic Lapis
Først fremstillet i 50'erne, den består af grynede blå spinel farvet af cobaltoxid og guld flager at lignesvovlkis. Materialet er meget hårdere, hvilket gør det lettere at skelne forskel

Rekonstrueret Lapis

Små chips af lapis og svovlkis cementeret sammen på samme måde rekonstruerede turkis er lavet

Farvet Lapis

En god kvalitet af ringere kvalitet lapis er farvet for at forbedre den blå tone, når stenen er farvet det ofte olie eller voks-at forbedre glans 

Farvet Howlite

Hvid Howlit er farvet for at skabe en lapis erstatning, farvestoffet tendens til at falme, og der er ingen svovlkis optagelser. 

Mountain Jade Lapis

Denne sten er ikke Jade eller Lapis, men en dolomit marmor farvet lyse blå! En anden sten, at farven falmer og der er ingen optagelser af svovlkis

Tysk Lapis

Også kaldet Swiss Lapis, en blå farvet Jasper, der også mangler i svovlkis inclusions 

Fejlidentifikation 

Sodalite

sodalit er en af de komponenter, der gør op Lapis, men selve stenen er faktisk mere indigo derefter lapis og mangler svovlkis. En anden måde at se forskel er en stribe test, Lapis har en lys blå stribe, mens sodalit har en hvid stribe 

Azurite

Azurite normalt danner skorper langs siden malakit, men når det danner krystaller kan det mig utroligt!Farven er meget mørkere, så dybt, at det er næsten sort. Azurite er også meget blødere derefter Lapis, kun en 3,5-4 på skalaen. 

Dumortierite

Dumortierite er en mørkere indigo end Lapis, og desuden mangler den svovlkis optagelser.

Lapis Lazuli from Afghanistan

Sar-e-Sang Mine, Jurm, Afghanistan

Royal blå lapis lazuli, at perle forskellige lazurite og en af de smukkeste uigennemsigtig smykkesten, er et natrium og aluminium mineralske af stor kompleksitet. Kendt som "safirer" af de gamle sten forekommer kun i et par store indskud i hele verden, især Bajkalsøen i Sibirien, Ocalle 
lapis lazuli, Afghanistan, Sar-e-Sang, afghanske lapis, Peter Bancroft De gamle kongelige sumeriske gravkamre i Ur, beliggende nær floden Eufrat i lavere Irak, indeholdt mere end 6000 smukt udført lapis lazuli statuetter af fugle, hjorte, og gnavere samt retter, perler, og cylinder sæler. Disse udskårne artefakter utvivlsomt kom fra materiale, der udvindes i det nordlige Afghanistan.Senere egyptiske gravpladser dating før 3000 f.Kr. indeholdt tusindvis af smykker emner, mange af lapis. Pulveriseret lapis blev foretrukket af egyptiske damer som et kosmetisk øjenskygge og i de senere år er det blev brugt som et pigment for ultramarin maling. Plinius den Ældre beskrev sten som "et fragment af den stjerneklare himmel." 
 Den mest værdsatte lapis er en mørk, næsten sortbrune blå, langt dybere end turkis og mere intens end sodalit eller Azurite. Lazurite forekommer hyppigst i lysere nuancer ofte blandet med striber af calcit. Selv attraktiv, dette materiale er mindre ønskeligt, og dermed henter en lavere pris. Svovlkis, en ofte forbundet mineral, er ofte gavmildt drysset hele lapis enheder, at skabe en slående blanding af rige blå og brassy guld.

Lapis lazuli 
Størrelse: 9 ved 6 cm 
Locality: Sar-e-Sang

lapis lazuli, Afghan lapis, lapis, sar-e-sang, Peter Bancroft, gem & crystal treasures

Ruten til lapis miner i Kokcha Valley er lang, indviklet og farlig. Fra Feysbad, hovedstaden i Afghanistans nordøstlige provins Badakhshan, en fattig vejstrækninger sydover gennem små landsbyer af mudder-walled hytter står på ujævnt underlag hærget af jordskælvet i 1832. Efter motorsport så vidt Hazarat-Said, skal den rejsende tilbringe en anden hel dag på hesteryg, før de når Kokcha Valley. Den lille Kokcha-floden er den østlige biflod til floden Oxus, som Marco Polo gennemkøres og skrev: "Der er et bjerg i regionen hvor de fineste azurblå [lapis lazuli] i verden er fundet. Det forekommer i venerne som sølv striber. "

Map of Afghanistan showing the location of the lapis lazuli mines. (Illustration ©Richard Hughes)
   Den lapis brydes på de stejle sider af en lang, smal besmitte undertiden kun 200 meter bred og bakkes op af forrevne tinder, der rejser sig over 6.000 meter. Tyndt befolkede og dækket med sne for meget af det år, de golde regionen er beboet af Wild Hogs og ulve. Sommeren Solen er glohed, men temperaturen falder under frysepunktet om natten. Britiske hær Løjtnant John Wood nåede lapis miner for East India Company i 1837, og skrev i sin rejse til kilden til floden Oxus, "Hvis du ikke ønsker at dø, undgå Valley of Kokcha." Dette er helt sikkert ikke en af verdens bedste steder for et felt tur!
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
Pack tog i høj, øde og meget kolde Kokcha Valley
Darreh-Zu, en af de ældste miner langs Kokcha, er nu lukket, og formentlig opbrugt. Den nærliggende og relativt nye Sar-e-Sang-minen i øjeblikket giver store mængder af god kvalitet perle materiale og har produceret sjælden 5-centimeter lazurite krystaller. Den største fundet hidtil, et velformet dodekahedron integreret i calcit, blev indsamlet i 1964 af Pierre Bariand, mineralsk indsamling museumsinspektør på Sorbonne. 
 Lazurite perle indskud sker i hvid og sort marmor hundrede meter tyk. The Gem vener, sjældent over 10 meter i længden, ligger i snehvide calcit. Tilknyttet mineraler omfatter svovlkis, diopside, sodalit, forsterite, Phlogopite, granat, dolomit, apatit, og afghanite, en forholdsvis ny art af cancrinite gruppe. Gem lazurite er fundet i tre persisk farve klassifikationer: nili (mørkeblå), assemani (lyseblå), og sabz (grøn).
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
Den Sar-e-Sang er højt på en klippe, men har produceret den største lapis lazuli krystaller af hele tiden
 I løbet af 1880'erne og begyndelsen af 1900'erne, blev lazurite udvindes af "brand-sæt"-metoden: store brande blev tændt på tunnelen ansigtet og derefter slukkes med vand. Den pludselige afkøling forårsaget ansigt klipper splintres, forenkle fjernelsen af malm. I GEM materiale blev derefter cobbed væk fra dens matrix. En kritisk mangel på træ og tilgængeligheden af sprængstoffer i sidste ende gjorde teknik forældet. 
Mange førende museer indslag billedskærerarbejder og smykker formet fra Kokcha lapis. Men ingen steder er den perle mere overdådigt vises end i Leningrad's Hermitage Museum, hvor dyb-blå figurer og vaser stå 2 meter høj. 
 Den Sar-e-Sang-minen har reserver af høj kvalitet lapis lazuli og eventuelt flere af de meget sjældne lapis krystaller. Men den politiske ustabilitet i Afghanistan skyer i fremtiden for både brydning og distribution af de ædle blå perle.
lapis lazuli, Afghanistan,Sar-e-Sang,Afghan lapis, Peter Bancroft
Lazurite krystal i marmor.
Størrelse af krystal: 5 cm; Locality: Sar-e-Sang 

 

Indledning. Lapis lazuli er en af de ældste af alle ædelstene, med en historie strækker sig tilbage de 7000 år eller mere. Dette mineral er vigtigt, ikke bare som en perle, men også som et pigment, for ultramarin er fremstillet af knust lapis lazuli (dette er grunden til, gamle malerier brug ultramarin for deres blå pigmenter aldrig fade).

Farve. For lapis lazuli, vil de fineste farve blive et endnu, intens blå, let støves af med små pletter af gyldne svovlkis. Der må ikke være hvide calcit vener er synlige for det blotte øje og svovlkis skal være lille i størrelse. Dette skyldes, at inddragelsen af svovlkis ofte producerer misfarvning i kanten, som ikke er så attraktiv. Sten, som indeholder for meget calcit eller svovlkis er ikke så værdifulde.

Klarhed. Lapis lazuli er hovedsagelig uigennemsigtigt med det blotte øje. Dog bør fine sten har ingen revner, der kan lavere holdbarhed.

Klip. Lapis lazuli er skåret i lighed med andre dekorative sten. Cabochons er fælles, som er flade poleret plader og perler. Indgraveringer og figurer er også almindelige.

Priser. Lapis lazuli er ikke en dyr sten, men rigtig fint materiale er stadig sjældne. Lavere kvaliteter kan sælge for mindre end 1 $ per karat, mens Superfin materiale kan nå op på $ 100-150/ct. eller mere i detailleddet.

Stone Størrelser. Lapis lazuli kan forekomme i flere kilogram store stykker, men top-grade lapis af selv 10-20 karat klippe er sjælden.

Navn. Navnet lapis betyder sten. Lazuli er afledt af det persiske lazhward, hvilket betyder blå. Dette er også årsagen til vores ord, azurblå.

Kilder. Oprindelige lokalitet for lapis lazuli er Sar-e-Sang deponering i Afghanistan fjernbetjening Badakhshan-distrikt. Dette minen er en af de ældste i verden, der producerer uafbrudt i over 7000 år. Mens andre indskud af lapis er kendt, ingen er af betydning i forhold til Afghanistan. Lapis lazuli findes også i Chile, hvor materialet er stærkt marmoreret med calcit. Små beløb er også udvindes i Colorado, nær Bajkalsøen i Sibirien, og i Burmas Mogok Stone Tract.

Ekstraudstyr. De mest almindelige forbedring af lapis lazuli er ved at dø (farvning), hvor en sten med hvide calcit optagelser farves blå at forbedre farven. Andre forbedringer, der almindeligvis opfattes som voksning og harpiks impregnations, igen, for at forbedre farve. Farven af farvede lapis er ustabil og vil forsvinde med tiden. Som med alle ædelstene, er det en god ide at have nogen større testet køb af et velrenommeret perle lab, at afgøre, om en perle er forbedret.

Efterligninger. Sintret syntetiske blå spinel engang blev brugt som en efterligning af lapis lazuli, men er sjældent set i dag. Såkaldte syntetiske lapis lazuli (såsom Gilson produkt) er mere korrekt at kalde en efterligning, da det ikke passer nøjagtigt struktur og egenskaber af det naturlige. Det findes i forskellige former, komplet med svovlkis pletter (men alle mangler calcit).Forskellige former for glas og plast er også almindeligvis opfattes som lapis efterligninger.

 

lapis lazuli ring
Ovenstående sten er et eksempel på, hvorfor afghanske lapis lazuli er i en liga alle sine egne. 

Egenskaber af lapis lazuli

Sammensætning Rock lavet primært af lazurite (Na, Ca) 8 (Al, Si) 12 O 24(S, SO 4). Indeholder også haüyne, sodalit og nosean, som alle er medlemmer af sodalit gruppe.
Hårdhed (Mohs) Variabel. Generelt 5-6
Vægtfylde Variabel. Generelt 2,7-2,9
Brydningsindeks ca. 1,50
Crystal System Ingen (lapis er en rock). Lazurite, hovedbestanddel, er isometrisk, og ofte optræder som dodecahedra.
Farver

Blå, marmoreret med hvide calcit og brassy svovlkis

Pleochroism Ingen
Phenomena Ingen
Håndtering På grund af sin blødhed, skal man være omhyggelig i brugen af lapis lazuli.
Ofte farvet eller imprægneret
Syntetisk til rådighed? Ja

From Wikipedia, the free encyclopedia

Lapis lazuli

En poleret stykke af lapis lazuli.
 
General
Kategori Rock
Kemisk formel blanding af mineraler
Identifikation
Farve Blå, marmoreret med hvide calcit og brassysvovlkis
Crystal habit Kompakt, massive
Crystal-system Ingen, som lapis er en klippe. Lazurite,hovedbestanddel, der ofte optræder som dodecahedra
Kavalergang Ingen
Fracture Ujævne-Conchoidal
Luster kedelig
Streak lyseblå
Vægtfylde 2,7-2,9
Brydningsindeks 1,5
Andre karakteristika Variationerne i sammensætningen forårsage en bred variation i de ovennævnte værdier.

Lapis lazuli (udtales / læpɪs læz (j) ʊ laɪ / eller / læzj ʊ li / LAP-ISS LAZ -yu-lye/lee [1]) (ofte forkortet til lapis)er en forholdsvis sjælden, halv-ædelsten, der har været værdsat siden antikken for sine intense blå farve.

Lapis lazuli er blevet udvundet i Badakhshan-provinsen i Afghanistan for over 6000 år, og handelen med stenen er gamle nok til lapis smykker at have fundet på Predynastic egyptiske steder, og lapis perler påneolitiske begravelser i Mehrgarh, den Kaukasus, og selv så langt fra Afghanistan som Mauretanien. [2]

 

Lapis lazuli (pronounced /ˈlæpɪs ˈlæz(j)ʊlaɪ/ or /ˈlæzjʊli/ LAP-iss LAZ-yu-lye/lee[1]) (sometimes abbreviated to lapis) is a relatively rare, semi-precious stone that has been prized since antiquity for its intense blue color.

Lapis lazuli has been mined in the Badakhshan province of Afghanistan for over 6,000 years, and trade in the stone is ancient enough for lapis jewelry to have been found at Predynastic Egyptian sites, and lapis beads at neolithic burials in Mehrgarh, the Caucasus, and even as far from Afghanistan as Mauritania.[2]

 

Description

Rå og polerede lapis lazuli.

Lapis lazuli er en sten, ikke en mineralsk: henviser til, at et mineral er kun en komponent, lapis lazuli er dannet af mere end en mineralsk. [3]

Den vigtigste bestanddel af lapis lazuli er lazurite (25% til 40%), en feldspathoid silikat mineral, der består af natrium, aluminium, silicium, ilt, svovl, og chlorid. Dens formel er (Na, Ca) 8 (AlSiO 4) 6 (S, SO 4, Cl) 1-2. [4]De fleste lapis lazuli indeholder også calcit (hvid), sodalit (blå), og svovlkis (metallisk gul) . Andre mulige vælgere er augite, diopside, enstatite, glimmer, hauynite, hornblende, og nosean. Nogle indeholde spormængder af den svovl rige lollingite sort geyerite.

Lapis lazuli forekommer normalt i krystallinsk marmor som følge af kontakt metamorphism.

Den fineste farve er intens blå, let støves af med små pletter af gyldne svovlkis. Stones uden hvide calcitvener og kun små svovlkis optagelser er mere værdsat. Pletter af svovlkis er en vigtig hjælp til identifikation af sten som ægte og ikke mindsker sin værdi. Ofte inferior lapis er farvet for at forbedre sin farve, der producerer en meget mørk blå med en bemærkelsesværdig gråjern, der kan også vises som en mælkeagtig nuance.

Bruger

Lapis er en fremragende polsk og kan gøres til smykker, billedskærerarbejder, æsker, mosaikker, smykker, og vaser. arkitekturen er det blevet brugt til beklædning af vægge og søjler af paladser og kirker.

Det var også stedet, og forarbejdet til det pigment ultramarin for tempera maling og, mere sjældent,oliemaling. Dens anvendelse som pigment i oliemaling endte i begyndelsen af det 19. århundrede som en kemisk identiske syntetiske sorter, ofte kaldet Fransk Ultramarin, blev tilgængelige.

Etymologi

Lapis er latin for 'sten' og lazuli i genitiv form af den middelalderlige latinske lazulum, som er fra arabisklāzaward, hvilket i sidste ende fra den persiske لاژورد lāzhvard, navnet på et sted, hvor lapis lazuli blev brudt.[5] [ 6] Navnet på det sted, kom til at være forbundet med sten udvindes der og i sidste ende, med sin farve. Det engelske ord azurblå, den franske Azur, den spanske og portugisiske Azul, og den italienskeAzzurro er sproglige slægtskab. Taget som helhed, lapis lazuli betyder 'sten af Lāzhvard «.

Kilder

Den bedste lapis lazuli findes i kalken i Kokcha River Valley i Badakhshan-provinsen i det nordøstligeAfghanistan, og disse aflejringer i minerne i Sar-e-Sang har arbejdet i mere end 6.000 år. [7] Afghanistan var kilden til lapis for de gamle egyptiske og mesopotamiske civilisationer, såvel som den senere græske og romerske; i højden af Induskulturen omkring 2000 f.Kr., den Harappan kolonien nu er kendt som Shortugaiblev etableret i nærheden af lapis miner. [2]

Ud over de afghanske indskud, har lapis blevet udtrukket i årevis i Andesbjergene nær Ovalle, Chile, hvor den dybe blå sten konkurrere i kvalitet med dem fra Afghanistan. Andre mindre vigtige kilder omfatterBajkalsøen regionen i Rusland, Sibirien, Angola, Burma, Pakistan, USA (Californien og Colorado), Canada ogIndien.

Kulturel og historisk / mytisk usage

En mesopotamiske lapis lazuli pendel ca. 2900 fvt.
En 11 cm (4,3 tommer) lange lapis lazuli dove besat med guld pinde.Elamitisk. Dateret 1200BCE fraSusa, Iran.
En Elephant carving i høj kvalitet lapis lazuli, der viser guldfarvede inklusioner af svovlkis.Udskæringen er 8 cm (3,1 i) lange.
Udskårne lapis lazuli af et bjerg scene, fra den kinesiske Qing-dynastiet (1644-1912).

 det gamle Egypten lapis lazuli var en favorit sten til amuletter og smykker som scarabs, og det blev også brugt af assyrerne og babylonierne for sæler. Lapis smykker er fundet ved udgravninger af Predynastic egyptiske site Naqada (3300-3100 f.Kr.), og pulveriseret lapis blev brugt som eyeshadow ved Cleopatra. [2]

Som indskrevet i den 140. kapitel i den ægyptiske dødebog, lapis lazuli, i form af et øje, der er i guld, blev anset for en amulet af stor magt. På den sidste dag i måneden, var et tilbud fremsat før denne symbolske øje, for man mente, at den dag, den øverste placeres sådan et billede på hans hoved. [Redigér]

De gamle kongelige sumeriske gravkamre i Ur, beliggende nær floden Eufrat i lavere Irak, indeholdt mere end 6000 smukt udført lapis lazuli statuetter af fugle, hjorte, og gnavere samt retter, perler, og cylinder sæler. Disse udskårne artefakter utvivlsomt kom fra materiale, der udvindes i Badakhshan i det nordligeAfghanistan. Meget sumerisk og akkadisk poesi omtaler lapis lazuli som en perle sømmeligt kongelig pragt.[Redigér]

I gamle dage var lapis lazuli kendt som safir, [8], som er det navn, der bruges i dag til den blå korund sort safir. Det ser ud til at have været den safir af antikke forfattere, fordi Plinius refererer til sapphirus som en sten drysses med pletter af guld. En lignende reference kan findes i den hebraiske Bibel i Job 28:6. Bibelen (New Living Translation) nævner også lapis lazuli i Anden Mosebog 24:10, hvor Gud selv synes at stå på den, mens på Mount Sinai.

Mange af blues i maleri fra middelalderen illuminerede manuskripter til renæssancen paneler er afledt af lapis lazuli. Terræn til et pulver og behandlet for at fjerne urenheder og isolere den komponent lazurite, den danner pigment ultramarin. Det klare, lyse blå, som var en af de få til rådighed for malere, før det 19. århundrede, koste en fyrstelig sum. Som tempera maleri blev afløst af fremkomsten af oliemaling i renæssancen, malere konstateret, at den brillans ultramarin blev stærkt formindsket, da den blev jorden i olie, og dette, sammen med sine omkostninger, har ført til et støt fald i brugen. Da syntetisk version af ultramarin blev opdaget i det 19. århundrede (sammen med andre 19th century blues, som kobolt blå), har indstillet produktionen og brugen af det naturlige sort næsten, men i flere pigment virksomhederne stadig producere det, og nogle malere er stadig tiltrukket til dens glans og dens romantiske historie.