Lapis lazuli

From New World Encyclopedia


Lapis lazuli
Lapis lazuli block.jpg
General
CategoryRock
Chemical formulamixture of minerals
Identification
ColorBlue, mottled with white calcite and brassy pyrite
Crystal habitCompact, massive
Crystal systemNone, as lapis is a rock. Lazurite, the main constituent, frequently occurs as dodecahedra
CleavageNone
FractureUneven-Conciodal
Mohs Scale hardness5 - 5.5
Lusterdull
Refractive index1.5
Streaklight blue
Specific gravity2.7 - 2.9
{{{density}}}
Other CharacteristicsThe variations in composition cause a wide variation in the above values.

Lapis lazuli, also known as lapis, is a stone with one of the longest traditions of being considered a gem, with a history stretching back to 7000 B.C.E. in Mehrgarh of Indian subcontinent, situated in modern day Balochistan, Pakistan. Deep blue in color and opaque, this gemstone was highly prized by the pharaohs of ancient Egypt, as can be seen by its prominent use in many of the treasures recovered from pharaonic tombs. It is still extremely popular today.

Lapis is a rock and not a mineral because it is made up from various other minerals. To be a true mineral it would have one constituent only.[1]

The first part of the name is the Latin lapis, meaning stone. The second part, lazuli, is the genitive form of the medieval Latin lazulum, which came from Arabic (al-)lazward, which came from Persian لاژورد lāzhward. This was originally a place-name, but soon came to mean blue because of its association with the stone. The English word azure, the Spanish and Portuguese azul, and the Italian azzurro are cognates. Taken as a whole, lapis lazuli means "stone of azure".

Description

The main component of lapis lazuli is lazurite (25% to 40%), a feldspathoid silicate mineral composed of sodium, aluminium, silicon, oxygen, sulfur, and chlorine. Most lapis also contains calcite (white), sodalite (blue) and pyrite (yellow). Other possible constituents are augite, diopside, enstatite, mica, hauynite, hornblende and nosean. Lazurite's formula is (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2. [2]

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. There should be no white calcite veins and the pyrite inclusions should be small. Stones that contain too much calcite or pyrite are not as valuable. 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, but these are often a very dark blue with a noticeable grey cast.

Sources

The finest lapis comes from the Badakshan area of Afghanistan. This source of lapis may be the oldest continually worked set of mines in the world, the same mines operating today having supplied the lapis of the pharaohs and ancient Sumerians. Using this ancient source, the Indus Valley Civilization's artists used to make beautiful carvings and traders used to trade them to distant places. More recently, during the 1980s conflict with the USSR, Afghanistan resistance fighters disassembled unexploded Soviet landmines and ordnance and used the scavenged explosive to help mine lapis to further fund their resistance efforts.[citation needed]

In addition to the Afghan deposits, lapis has been found in the Andes near Ovalle, Chile, where it is usually pale rather than deep blue. Other less important sources are the Lake Baikal region of Russia, Siberia, Angola, Burma, Pakistan, USA (California and Colorado), Canada and India.

Uses

Lapis takes an excellent polish and has been 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 nineteenth century as a chemically identical synthetic variety, often called French Ultramarine, became available.

Cultural and historical/mythical usage

A Mesopotamian lapis lazuli pendant circa 2900 B.C.E.
An Elephant carving in high quality lapis lazuli, showing gold-colored inclusions of pyrite. These inclusions are common in lapis and are an important help in identifying the stone. The carving is 8 cm (3 inches) long.

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. Egyptian burial sites dating before 3000 B.C.E. contained thousands of jewelry items, many of lapis. Powdered lapis was used by Egyptian ladies as a cosmetic eye shadow.

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.

The ancient royal Sumerian tombs of Ur, located near the Euphrates River in lower Iraq, contained more than 6,000 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. The word lazuli itself originates from the Persian dialect of Badakhshan. Much Sumerian and Akkadian poetry makes reference to lapis lazuli as a gem befitting royal splendor.

In ancient times, lapis lazuli was known as sapphire, 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 Romans believed that lapis was a powerful aphrodisiac. In the Middle Ages, it was thought to keep the limbs healthy, and free the soul from error, envy and fear.

It was once believed that lapis had medicinal properties. It was ground down, mixed with milk and applied as a dressing for boils and ulcers.

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 nineteenth 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 nineteenth century (along with other nineteenth-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.

Poetry/Literature

Lapis Lazuli is a poem written by William Butler Yeats. Text available at Readprint.com

As noted above, lapis lazuli is also repeatedly mentioned in the Sumerian and Akkadian Epic of Gilgamesh. For instance, the Bull of Heaven's horns are composed of Lapis lazuli.

Lapis Lazuli is also mentioned in Browning's 'The Bishop Order's His Tomb at Saint Praxed's Church'.

Lapis lazuli also makes an appearance in Marianne Moore's poem, "A Talisman" - which is quoted by T. S. Eliot in his "Introduction to Selected Poems [of Marianne Moore]." The stanza of Moore's poem reads: "Of lapis-lazuli,/A scarab of the sea,/With wings spread-". Eliot, in the next paragraph, raises the question: "I cannot see what a bird carved of lapis-lazuli should be doing with coral feet; but even here the cadence, the use of rhyme, and a certain authoritativeness of manner distinguish the poem."

In Lorna Crozier's poem "The Memorial Wall", "a young man who'd come/ from Montana to find his brother's name,/paints te side door lapis lazuli".

In Robert Heinlein's novel, "Time Enough for Love," the centuries old main charater, Lazarus Long, names one of his two twin cloned daughters Lapis Lazuli.

See also

Notes

References
ISBN links support NWE through referral fees

  • Farndon, John. 2006. The Practical Encyclopedia of Rocks & Minerals: How to Find, Identify, Collect and Maintain the World's best Specimens, with over 1000 Photographs and Artworks. London: Lorenz Books. ISBN 0754815412 and ISBN 978-0754815419.

External links

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