WORLD OF GEM STONE

Tuesday, July 21, 2009

Malachite

Gemstones: Malachite

Malachite cultivated
Malachite cultivated


Malachite cultivated


Malachite untreated


Malachite untreated


Malachite untreated

Malachite -- a talisman for children.

Color: Malachite is an opaque, banded stone, the colors in the bands range from a very light green to almost deep green.

Description: Cu2CO3(OH)2 , Malachite is a semi-precious stone and also a valuable copper ore, hydrous copper carbonate. It is responsible for the green color of tarnished copper and bronze. Because of its distinctive bright green color and its presence in the weathered zone of nearly all copper deposits, malachite serves as a prospecting guide for that metal. Malachite has been used as an ornamental stone and as a gemstone.

The name's origin: Malachite derives its name from Greek word malakos - soft. According to another theory the word malachite comes from Greek malhe, which means grass.

Wedding anniversary: Malachite is the anniversary gemstone for the 13th year of marriage.

Care and treatment: Malachite is especially fragile. Protect malachite from scratches and sharp blows. Also avoid large temperature changes. Do not clean malachite in a home ultrasonic cleaner. Washing malachite in water will remove its protective polish. If setting or repairing in jewelry be careful of heat since a jeweler's torch can damage the stone.

From the stone history: Mining Malachite began as early as 4000 BC by ancient Egyptians. In the Middle ages, malachite was worn to protect from black magic and sorcery. In Ancient Greece amulets for children were made of malachite.
In the New Stone Age came the discovery of the possibility of extracting certain metals from the ores in which they generally occur. Probably the first such material to be used was malachite, then already in use as a cosmetic and easily reduced to copper in a strong fire. It is impossible to be precise about the time and place of this discovery, but its consequences were tremendous. Namely it led to the search for other metallic ores, to the development of metallurgy.

Shopping guide: Malachite is a beautiful green earth stone with irregular black banding. It is easily recognized by its color, green streak, and silky or velvety lustre. It is beautiful in earrings, necklaces, and pendants. Imitation malachite has very regular black or white banding.

Healing ability: Malachite is said to aid in the regeneration of body cells, creates calm and peace, and aids one's sleep.

Mystical power: A gorgeous stone, Malachite is worn by many to detect impending danger. This beautiful green stone offers bands of varying hues and is believed by many to lend extra energy. It is believed that gazing at Malachite or holding it relaxes the nervous system and calms stormy emotions. Malachite is said to bring harmony into one's life. It is also believed that malachite gives knowledge and patience. Malachite is used as a children's talisman to ward off danger and illness. It is attached to infant's cradles.

Deposits: The most important mine is in Zaire. Notable occurrences are in Ural, Siberia, France, South Australia, Namibia and USA (Arizona).

Sodalite

Sodalite


SodaliteSodalite is named in reference to the sodium content it has. It is found in light to dark pure blue color and is well known in the semi-precious stone world. It is the only feldspathoid which contains chlorine.

Sodalite balances the mental and emotional bodies. It cleanses the aura, soothes and calms inflammations. It fuels a person's creative processes and also enhances wisdom. It helps to make clear and rational decisions. It builds self confidence, helps fight lymphatic cancer and also boost the immune system.

Sodalite is found in Namibia, Brazil, Canada and the USA. The hardness is 6 and specific gravity, 2.13 - 2.29.

Lapis Lazuli

Gemstones: Lapis Lazuli

Lapis Lazuli
Lapis Lazuli
Lapis Lazuli
Lapis Lazuli
Lapis Lazuli round plate
Lapis Lazuli
Statuette of goat made of Lapis Lazuli

Lapis Lazuli is a gemstone compared to stars in the sky.

Stone's names: Lapis Lazuli, Lazurite.

Color: Lapis Lazuli occurs in various shades of blue with some qualities being speckled with white calcite and some with yellow pyrite. The finest Lapis Lazuli is even blue color with little or no veining from other elements.

Description: Lapis lazuli is a semiprecious stone valued for its deep blue color. The source of the pigment ultramarine, Lapis lazuli is not a mineral but a rock colored by lazurite. In addition to the sodalite minerals in lapis lazuli, small amounts of white calcite and of pyrite crystals are usually present.
Because lapis is a rock of varying composition, its physical properties are variable.

The name's origin: The name lapis comes from word pencil in Spanish.

Wedding anniversary: Lapis Lazuli is the anniversary gemstone for the 7th and 9th year of marriage.

Care and treatment: Lapis Lazuli can easily be scratched or chipped. Water can dissolve the stone's protective coatings, hence clean your lapis lazuli jewelry with a soft dry cloth.

From the stone history: Lapis Lazuli with deep azure blue color, often flecked with golden pyrite inclusions, was treasured by ancient Babylonian and Egyptian civilizations and often worn by royalty. Lapis lazuli was widely used by Egyptians for cosmetics and painting . Persian legend says that the heavens owed their blue color to a massive slab of Lapis upon which the earth rested. Lapis Lazuli was believed to be a sacred stone, buried with the dead to protect and guide them in the afterlife.
Lapis lazili is one of the gemstones, that used incommesso, also called florentine mosaic. Commesso is a technique of fashioning pictures with thin, cut-to-shape pieces of brightly colored, semiprecious stones, developed in Florence in the late 16th century. The stones most commonly used are agates, quartzes, chalcedonies,jaspers, granites, porphyries, petrified woods, and lapis lazuli. Commesso pictures, used mainly for tabletops and small wall panels, range from emblematic and floral subjects to landscapes.
Visit all-that-gifts.com - the online store that offer a large collection of pictures decorated with natural precious and semiprecious stones.
For centuries Lapis Lazuli has been prized for jewelry. But it has also been used to make the beautiful blue paint ultramarine and has been used as a source of writing instruments. Ultramarine is used in paints, lacquers, and decorating materials. It has a particularly brilliant blue color and is very lightfast.

Shopping guide: Lapis lazuli has been widely used as a semiprecious stone throughout history. It is most often seen as a necklace of beads or carved pendants.
Fine natural Lapis Lazuli can be rather pricey. Jewelry with the high quality stones with no calcite or pyrite veins can be quite expensive. Much of the jewelry that is sold as Lapis is an artificially colored jasper from Germany that shows colorless specks of clear, crystallized quartz and never the goldlike flecks of pyrite.

Healing ability: The stone is said to increase psychic abilities. Lapis is said to be a cure for melancholy and for certain types of fever. Lapis lazuli eliminates negative emotions. It relieves sore throat pain.

Mystical power: Traditionally believed to increase mental clarity, virility, and calm. Lapis Lazuli is energy focuser for teachers, lecturers and speakers. Enhances creative self-expression. It is believed to be useful in relieving depression and promoting spirituality. Lapis Lazuli is also powerful during meditation.

Deposits: The main supplies of Lapis Lazuli are found in the Afghanistan, Egypt, Canada, Chile, the US, and South America. The most important sources are the mines in Badakhshan, northeastern Afghanistan, and near Ovalle, Chile, where gemstone is usually pale rather than deep blue.


Dumortierite

Dumortierite

Dumortierite from Madagascar

Dumortierite is a fibrous variably colored aluminium boro-silicate mineral, Al6.5-7BO3(SiO4)3(O,OH)3. Dumortierite crystallizes in the orthorhombic system typically forming fibrous aggregates of slender prismatic crystals. The crystals are vitreous and vary in color from brown, blue, and green to more rare violet and pink. Substitution of iron and other tri-valent elements for aluminium result in the color variations. It has a Mohs hardness of 7 and aspecific gravity of 3.3 to 3.4. Crystals show pleochroism from red to blue to violet. Dumortierite quartz is blue colored quartz containing abundant dumortierite inclusions.

Dumortierite was first described in 1881 for an occurrence in Chaponost, in the Rhône-Alps ofFrance and named for the French paleontologist Eugene Dumortier (1803-1873). It typically occurs in high temperature aluminium rich regional metamorphic rocks, those resulting fromcontact metamorphism and also in boron rich pegmatites. The most extensive investigation on dumortierite was done on samples from the high grade metamorphic Gfohl unit in Austria by Fuchs et al. (2005).

It is used in the manufacture of high grade porcelain. It is sometimes mistaken for sodalite and has been used as imitation lapis lazuli.

Sources of Dumortierite include Austria, Canada, France, Italy, Madagascar, Namibia,Nevada, Norway, Poland, Russia and Sri Lanka

Benitoite

Benitoite

Benitoite

Benitoite on natrolite
General
CategorySilicate mineral
Chemical formulaBaTiSi3O9
Identification
ColorBlue; Colorless
Crystal habitTabular dipyramidal crystals, granular
Crystal systemHexagonal
Cleavage[1011] Poor
FractureConchoidal
Mohs Scalehardness6 - 6.5
LusterVitreous
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity3.6
Refractive index1.757-1.759; 1.802-1.804
PleochroismDichroic (blue to white)
SolubilityInsoluble: HCl, H2SO4
Soluble: HF
References[1][2]

Benitoite is a rare blue barium titanium silicate mineral, found in hydrothermally alteredserpentinite. Benitoite fluoresces under short wave ultraviolet light, appearing light blue in color.

It was first described in 1907 by George D. Louderback, who named it benitoite, “as it occurs near the head waters of the San Benito River in San Benito County,” California.[3][4]

Uses of benitoite

Benitoite's main uses are as collector's specimens, especially in specimens which show off this mineral's unique crystals, or specimens in which benitoite occurs with its commonly associated minerals. Benitoite's hardness also makes it suitable for use as a gemstone, though the general lack of usable material has limited this use.

Associated minerals and locations

Benitoite typically occurs with an unusual set of minerals, along with minerals that make up its host rock. Frequently associated minerals include:

natroliteNa2Al2Si3O10 · 2H2O
neptuniteKNa2Li(Fe, Mn)2Ti2Si8O24
joaquiniteNaBa2FeCe2(Ti, Nb)2(SiO3)8(OH, F) · 1H2O
serpentine(Mg, Fe)3Si2O5(OH)4
albiteNaAlSi3O8
Blue Benitoite Crystals on white natrolite, Dallas Gem Mine, San Benito Co., California, USA

Benitoite is a rare mineral found in very few locations including San Benito County, California,Japan and Arkansas. In the San Benito occurrence it is found in natrolite veins withinglaucophane schist within a serpentinite body. In Japan it occurs in a magnesio-riebeckite-quartz-phlogopite-albite dike cutting a serpentinite body.[5] Benitoite is typically found with some combination of natrolite, joaquinite, and neptunite on a greenish-grey serpentinite base.

Benitoite is the official state gem of California.

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