Monday, June 7, 2010

Lapis Lazuli

Gemstone :
Lapis Lazuli

Birthstone Month :
Lapis Lazuli is listed as the traditionally associated with the month of December. It is also often used as an alternate birthstone for the month of September.

Zodiac :
Lapis Lazuli is associated with the zodiac signs of Capricorn, Libra, and Sagittarius.

Chemical Symbol :
(NaCa)8(AlSi)12O24(SSO4)

Chemical Make-up :
Lapis Lazuli is not a mineral, but a rock composed of a mixture of minerals including Lasurite, Huaynite, Sodalite, Noselite, Calcite, and Pyrite. The blue coloration is due to sulfuric Lasurite content.

History & Lore :
The name Lapis Lazuli is derived from the Latin 'lapis' meaning “stone”, and the Persian 'lazhward' meaning blue.

Today's most prominent source of fine quality Lapis Lazuli is the same ancient deposit in the Hindukush Mountains of Afghanistan where it was originally mined at least 6000 years ago. It is reported that there was a busy trade in Lapis Lazuli in the ancient city of Ur, situated on the Euphrat river.

Archaeological excavations in numerous locations around the Mediterranean have provided samples of jewelry left in ancient tombs. This jewelry often consisted of necklaces and objects crafted from Lapis Lazuli. Again and again these samples have been found, indicating that the people of Mesopotamia, Egypt, Persia, Greece and Rome cherished Lapis Lazuli.

Lapis Lazuli was pulverized and used as a paint coloration from pre-Renaissance times until 1834 when it became possible to manufacture the color (known as 'ultramarine' meaning “from beyond the seas”) artificially.

Pliny the Elder once referenced Lapis Lazuli as “a fragment of the starry firmament” in admiration of its deep blue color and twinkling gold Pyrite inclusions.

Lapis Lazuli has long been considered a stone of truth and friendship that can enhance the owner's awareness, insight and intellect. It has also been deemed a stone of peace and harmony, and can provide self-acceptance to help the wearer understand themselves as an authentic individual.

Physically, Lapis Lazuli is reputed to help cure, insomnia, depression, recurring fevers, and disorders of the throat, lungs and immune system.

Availability :
Afghanistan is the main source of fine Lapis Lazuli. It is rare elsewhere, particularly in good qualities, although other deposits do occur. Lapis Lazuli is available in a wide range of prices, ranging from modest to expensive.

Sources :
The most prominent deposits of Lapis Lazuli are still to this day the Hindukush Mountains of Northern Afghanistan. Other deposits include Canada, Chile, Italy, Mongolia, Myanmar (Burma), Pakistan, Russia, Siberia, and the United States.

Evaluation :
Lapis Lazuli is rated at 5 to 6 on the Moh's Scale of Hardness and should be worn and stored with care to avoid any permanent damage to the stone. Stones that appear dull because of excessive usage can be repolished to restore their original beauty.

Lapis Lazuli has long been admired for its intense deep blue color, with less desirable shades ranging through light grayish blue, to greenish blue, to a dark violet blue. Gold has long been considered the reason for Lapis Lazuli's twinkling inclusions that have often been referred to as resembling the glimmering night sky. However, these “Gold” inclusions are not actually gold at all, they are Pyrite. These Pyrite inclusions increase the value of the stone when finely distributed. White specks (Calcite inclusions), will generally reduce the value of a Lapis Lazuli stone, particularly when arranged in a spotty or irregular pattern.

The value of Lapis Lazuli is determined almost exclusively by the beauty and intensity of the color, with the most desired being the deep and intense blue. The quality of the polish and fashioning of the stone must also be taken into account.

Common Cuts :
Because Lapis Lazuli is a slightly soft, opaque gemstone it is most commonly and almost exclusively cut into cabochons, beads, and spheres. It has also been used in various carvings / small sculptures.

Lapis Lazuli creates a somewhat unpleasant experience for the cutter because of the foul smell that emanates from the stone when it makes contact with the cutting wheel. This smell is caused by the sulfuric contents of Lasurite.

Routine Enhancements :
Lapis Lazuli is commonly impregnated with colorless wax or synthetic resin in order to improve appearance and resistance against wearing. Stones with numerous white Calcite inclusions are also often dyed to improve their
coloration.

Care & Cleaning :
Lapis Lazuli is a relatively soft gemstone and should be worn and stored with care. That being said, It is still widely used in rings and bracelets, although it is wise to choose a protective setting when selecting Lapis Lazuli for setting in a ring.
If Lapis Lazuli becomes dull from constant wear, it can easily be repolished to restore its original beauty. Household chemicals, acids, ultrasonic cleaners, and prolonged exposure to excessive heat should all be avoided as they can cause permanent damage to the stone. Lapis Lazuli is best cleaned using warm soapy water and a soft brush.

Lapis Lazuli jewelry should be stored in a fabric-lined box away from other jewelry items so as to avoid damage / scratching.

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