What is artificial turquoise?

Turquoise is a hydrous phosphate of copper and aluminum with hydroxyl, forms an isomorphic series with chalcosiderite, the turquoise group.

Synonyms:

arizonite,
agapit (agathite),
arabic stone,
aztec stone,
genwoodite,
johnite,
zhonit,
ionite,
kalait,
kallait (kallais),
azure spar,
heavenly stone,
Sinai Stone,
turkish,
Henwoodite.

Chemical composition

The chemical composition is not constant. During the aging process and when replaced by secondary minerals, the role of iron oxide, silica, calcium, magnesium, zinc, and strontium increases. Chemical composition (in%): CuO – 9, Al57O2 – 3, Pb36,84O2 – 3, H34,12O – 2. Permanent impurities in birquoise are sulfur, zinc, barium, chromium, nickel, titanium, etc. Blue, turquoise color, characteristic of turquoise unaffected by weathering, depends on the copper content. Greenish, brownish and other tones are caused by oxide iron, which replaces copper in the zone of its intensive decomposition. Impurities of halloysite, kaolinite and wavellite give whitish spots. Often contains inclusions of quartz, pyrite and other minerals.

Diagnostic signs

The mineral is characterized by a greenish-blue color and waxy luster. However, in some cases, to distinguish chrysocolla, variscite and other copper minerals from sometimes similar to turquoise, it is necessary to resort to chemical reactions. Under item tr. cracks, turns brown. The flame turns the turquoise pale green. In a closed tube it releases a lot of water. With brown and phosphorus salts it reacts with copper. It dissolves in acids and reacts with phosphorus.

Forms of occurrence of turquoise: crystals are very rare and have a predominantly short-prismatic habit. Typically, turquoise forms cryptocrystalline dense masses, veins, crusts, small rounded inclusions, kidney-shaped and grape-shaped concretions, often with a characteristic cobweb pattern of thin black or brown veins when cut (mesh).

Origin and deposits of turquoise

The formation of turquoise is associated with hypergene or low-temperature (180°-80°C) hydrothermal processes. It is formed under weathering conditions (often together with limonite), during the action of copper-bearing surface solutions on rocks containing alumina (in feldspars, etc.) and phosphorus (in the form of apatite, etc.). There are known cases of the formation of turquoise due to fossil bones and teeth of animals (the organic origin of such turquoise is clearly established in thin sections under a microscope). The best turquoise was mined for a number of centuries in the Madan deposit (near Niishapura in Iran), where turquoise, together with limonite, formed in the form of irregular clusters and thin veins among weathered igneous rock – trachyte. Like a precious stone, turquoise was transported from here to Epropa through Turkey. Of the remaining deposits – Egypt, the Sinai Peninsula, Afghanistan, Central Asia (Biryuzakanskoye, Kalmakyrskoye, Ayakashi deposit and other deposits).

Application

They are used in jewelry production, depending on the quality – an ornamental or semi-precious stone. According to ancient beliefs, wearing this stone brings wealth or, at least, protects against the loss of what you have.

Pastel shades were a popular stone among many great cultures of antiquity: turquoise was used in the jewelry of the rulers of Ancient Egypt, the Aztecs, and was popular in Persia, Mesopotamia, the Indus Valley states, and in ancient China since the Shang Dynasty. Despite being one of the oldest gemstones, probably first introduced into Europe via Turkey with other gemstones via the Silk Road, turquoise did not become a prominent decorative stone in the West until the 14th century, but after the decline of Roman Catholic influence It became fashionable for the church to use turquoise in secular jewelry. Turquoise was apparently unknown in India before the Mungal period, and unknown in Japan until the 18th century.

The Aztecs used this stone in inlays with gold, quartz, malachite, jade, coral and mother-of-pearl, particularly in ceremonial masks (some of which were made from human skulls), for decorative trim on knives and shields. How the Aztecs, Pueblos, Navajo and Apache tribes used turquoise to create magical amulets.

In Persia it has been the national stone for thousands of years, widely used to decorate both small objects (from turbans to bridles) and mosques and other important buildings (Shah Hussein I Mosque of Isfahan). The Persian style and use of stone was later brought to India after the founding of the Mungal Empire, and there turquoise was used along with gold, diamonds and rubies in the creation of buildings such as the Taj Mahal. Cabochons of imported turquoise, along with coral, were widely used for setting in silver and gold jewelry in Tibet and Mongolia, where the green shade of the stone is most popular.
The Egyptians were the first to create an artificial imitation of turquoise in the form of an alloy made of earthenware.

Later imitations in glass and enamel were also used to imitate natural turquoise, and even later more complex ceramics, porcelains, plastics and alloys (for example, composed of various copper and aluminum components) began to appear: examples of the latter include “Viennese turquoise”, made from accelerated aluminum phosphate, colored with copper, and “neolith”, a mixture of bayerite and copper phosphate. Most of these products differ markedly from natural turquoise in both physical and chemical properties, but in 1972 Pierre Gilson produced synthetic turquoise with properties similar to natural stone.

Recently, artificial turquoise has been widely used (made from copper aluminophosphates, colored synthetic plastics or ceramics). The market also offers semi-synthetic varieties, in the production of which crushed waste from the natural one is used as additives in the synthetic base mass. A method has also been developed for the industrial synthesis of an analogue, which is very similar to the natural one, in laboratory conditions.

Bone turquoise

Odontolite (in Greek – bone stone), otherwise called bone turquoise. This is bone or dental phosphate of extinct large fossil mammals (mammoth, mastodon, dinoteria), colored turquoise with vivianite.

Bone turquoise is used as an imitation of natural turquoise. Areas where bone turquoise is widespread: Siberia, Southern France. Bone turquoise is very rare on sale and, with high-quality artistic finishing, is of great value.

Properties of the Mineral

Color	sky blue, bluish green to apple, grayish and brownish green shades
Line color	pale greenish blue fading to white
Origin of the name	From Persian پیروز‎ – victorious, English from Turkey (Turkey), from which the stone came to Europe
Opening year	Known since ancient times
IMA status	valid, first described before 1959 (before IMA)
Chemical formula	Cu(Al,Fe3+)6(PO4)4(OH)8 · 4H2O
Brilliance	glass wax dim
Transparency	transparent translucent shines through opaque
Cleavage	perfect by average for
Kink	conchoidal
Hardness	5 5,5 6
Thermal properties	Does not melt, releases a lot of water in a closed glass tube
Typical impurities	Fe,Ca
Strunz (8th edition)	7/D.15-40
Hey’s CIM Ref.	19.2.8
Dana (7th edition)	42.9.3.1
Dana (8th edition)	42.9.3.1
Molecular weight	813.44
Cell Options	a = 7.409(1) Å, b = 7.635(1) Å, c = 9.914(2) Å α = 111.356°, β = 114.973°, γ = 69.532°
Attitude	a:b:c = 0.97 : 1 : 1.298
Number of formula units (Z)	1
Unit cell volume	V 449.39 Å³
Point group	1 – Pinacoidal
Space group	P1
Density (calculated)	2.91
Density (measured)	2.6 – 2.8
Pleochroism	weak
Optical axis dispersion	r

View the Turquoise mineral in mineral stores

Photo of Mineral

Turquoise has been used since ancient times – rough stones of the Aztecs, jewelry with turquoise from the tombs of Egyptian pharaohs, stone-cutting crafts of Chinese craftsmen, magnificent turquoise jewelry of the peoples of Asia – and to the present day.

Turquoise mines in the Sinai Peninsula are the oldest operating mines. Turquoise mining began there as early as 6000 BC. e.

Turquoise deposits in Central Asia, in the Kurama and Chatkal ranges, are associated with quartz-vein zones of the porphyry formation.

Turquoise is a precious stone, in the occult tradition it is considered a magical stone, a talisman.
In the Middle Ages, Persian merchants transported turquoise in jugs of water.

With all the variety of imitations of turquoise, the number of works devoted to the true synthesis of this mineral is extremely limited. At the beginning of the 19th century, M. Hoffmann reported that he had obtained synthetic turquoise in two ways.

Turquoise is classified as an ornamental stone. The formation of turquoise is associated with low-temperature hydrothermal processes.

As for the magical properties of turquoise, it is believed that the stone supposedly dies (that is, loses its color) when the owner is in danger or illness.

In the paintings of artists of the Middle Ages, the richness of clothing and decoration was often emphasized by the presence of inlays, embroidery and gold or silver jewelry. Particularly beautiful is the sensual play of color on the delicate skin of the nude and the gold bracelets with azure turquoise elements.

According to ancient beliefs, this stone brings happiness, and its owner is lucky in all endeavors.

So, in order to successfully imitate real turquoise, you must first obtain the required color from plastic. As you know, turquoise comes in different shades (from light to dark, from greenish to bluish). Therefore, decide for yourself which color to choose.

Turquoise (from Persian firuze – “stone of happiness”, or Persian piruz – “victory”) is a mineral, hydrated phosphate of aluminum and copper, one of the most popular ornamental and semi-precious stones from ancient times to this day.

Origin of name.

The ancient French word turquoise apparently comes from the French pierre turquoise, which means Turkish stone. This opinion, however, was based on an inaccuracy: turquoise was not mined in Turkey, but was only exported from there along the “Great Silk Road” and was therefore associated with the East.

Origin.

The formation of turquoise is usually associated with supergene or low-temperature (180–80 °C) hydrothermal processes. Occurrences of turquoise are often associated with zones of secondary alteration of copper deposits.

There are known cases of the formation of turquoise due to fossil bones and teeth of animals (the organic origin of such turquoise is clearly established in thin sections under a microscope). The best turquoise was mined for a number of centuries in the Madan deposit (near Niishapur in Iran), where it, together with limonite, formed in the form of irregular clusters and thin veins among the weathered igneous rock – trachyte. Like a precious stone, turquoise was transported from here to Epropa through Turkey.

Forms of location.

Cryptocrystalline dense masses, veins, crusts, small round inclusions, round tuberculate nodules of cluster-like shapes. When cut, it often has characteristic mesh-like thin branching veins of black or brown color (“spider turquoise”).

Properties.

Color ranges from bright sky blue or bluish blue to bluish green and faded green. The luster is weak, waxy, opaque. There is no variance. Pleochroism is weak. Luminescence is usually absent, sometimes whitish or bluish.

Place of Birth.

Turquoise deposits are numerous, but their reserves are usually small, as a result of which targeted extraction of natural raw materials is quite expensive. Turquoise mining centers are known in many ancient civilizations, and some ancient mines are still in operation. However, much of the natural turquoise today is mined from large copper deposits as a by-product, particularly in the United States.

The main deposits are located in Egypt, China, the Sinai Peninsula, Iran, Central Asia (Biryuzakanskoye, Kalmakyrskoye, Ayakashi deposit and other deposits), the USA.

Turquoise processing.

Processed cabochon or in the form of plates for inserts. High quality turquoise is easy to grind, takes polish well, and retains its original color for a long time. Since ancient times, low-quality turquoise products have been lightly coated with resin or wax to add depth and shine to the porous matte surface, increasing water resistance and durability.

Imitations and falsification of turquoise.

The first who learned to imitate turquoise were the Egyptians. Later, crafts made of colored glass and porcelain appeared; from bone impregnated with copper salts, painted plastic masses (first – galalite and celluloid), and other simple imitations.

Some natural blue-green materials, such as chrysocolla with quartz, are sometimes confused with turquoise, or used in imitation.

Blue and blue material of different tones were sometimes ground into powder and then pressed together with powder or chips of natural turquoise, achieving the “natural” heterogeneity of the stone.

Today, mostly artificial turquoise is supplied to the retail chain. It is made from copper aluminophosphates, colored synthetic plastics and ceramic materials with coloring additives (sometimes natural turquoise waste is used as additives), and also imitates chrysocolla, variscite and blue-dyed howlite.

Traditions associated with turquoise.

For adherents of Islam, turquoise is a mandatory element of a bride’s wedding dress, as a symbol of virginity, purity and a future happy life together. Rings with turquoise, according to tradition, were exchanged on the day of engagement. They were given as a sign of attraction, they were symbols of eternal love.

USA
Egypt
China
Iran, Islamic Republic
Armenia

Buyer’s Reminder. What to look for when buying?

Designers all over the world are looking for good quality turquoise. Turquoise is evaluated according to three parameters: color, texture, and the presence or absence of a matrix.

Color.

The most valuable color is a smooth, bright medium blue. Some prefer greenish blue, and some designers look for avocado or lime green. As a rule, deep blue shades are considered the most valuable.

Purity.

Turquoise can be translucent or opaque, usually a light to medium shade of blue or greenish blue. Turquoise may contain matrix veins (remaining elements of the rock surrounding the turquoise) running through the stone. Spider Web Turquoise contains fine veins of matrix that form an attractive web of veins.

Cut.

Turquoise is most often cut into cabochons. Dome-shaped shapes convey the color, texture and beauty of the matrices well. In addition, manufacturers and artists fashion raw turquoise and beads into bracelets and pendants, and flat pieces are also popular in jewelry making.

The weight.

Turquoise is available in a wide range of sizes, although large specimens without visible matrix are rare. Native American jewelry uses all sizes. Large pieces are popular among stone carvers. For any size, quality and color uniformity are the main cost factors.