Turquoise is a high-quality jade material, the Europeans called it "Turkish jade" or "Turk jade".Turquoise is the world recognized "December birthday stone", on behalf of victory and success, there is a "success of the stone" reputation.
Turquoise due to the different elements contained, there are differences in color, oxide containing copper is blue, iron is green.Most of the sky blue, light blue, green blue, green, green pale color.Uniform color, soft luster, no brown wire of the best quality.
Color is an important factor affecting the quality of turquoise.Turquoise products beautiful color, by ancient and modern Chinese and foreign people.In order to protect mineral resources in China, some places explicitly prohibit mining, so businessmen import from abroad and then process turquoise in the mainland, and then sell the first ornaments and handicrafts to other places. Except for the Kesmere area, Lhasa is now the world's largest turquoise trading market.
Turquoise texture is delicate, soft, moderate hardness, delicate and charming color, but color, hardness, quality difference is larger.It is usually divided into four varieties, namely porcelain pine, green pine, bubble (noodles) pine and iron wire pine.
Turquoise is a phosphate mineral complex of copper and aluminum, most distinctive for its opaque azure color.There are light blue, blue green, green, light green, yellow green, gray green, pale color and other colors.The general hardness is 5~6, the density is 2.6~2.9, the refractive index is about 1.62.Long - wave ultraviolet light, light green to blue fluorescence.
Turquoise is one of the ancient gems, with thousands of years of brilliant history, by the ancient and modern people at home and abroad love.A.D. 5500 years ago, ancient Egypt on the Sinai Peninsula mining turquoise, the first dynasty when the king of Egypt had sent a well-organized and military escort of two or three thousand labor forces, looking for and mining turquoise.Archaeologists excavating ancient Egyptian tombs have found that Egyptian Kings were wearing turquoise beads as early as 5,500 BC.
Physical properties
Morphology: Triclinic, cryptocrystalline, rare microscopic crystals, can only be seen under a microscope.
Fracture: conch-shaped to granular (relative to porosity).
Hardness: the Mohs hardness of dense block is 5~6, the Mohs hardness of large porosity is small.
Toughness: chalky toughness is small, easy to fracture, dense toughness is good.
Stripe: white or green.
Relative density: 2.4~2.9, the standard value is 2.76
Transparency: Usually opaque.
Gloss: the polished surface is greasy glass luster, and the fracture is greasy dull luster.
Inclusion: often black spots or black linear brownite or other iron oxide inclusions.
Refractive index: NG=1.65,NM=1.62,NP=1.61.Because turquoise often appears as a green aggregate, there is only one reading on the gemstone refractometer, with an average of about 1.62.
Birefringent index: strong crystal birefringent index (DR), DR=0.040.But it doesn't show up on gemological tests.
Optical properties: positive optical properties of biaxial crystal, 2Y=40.Since turquoise is usually opaque, gemological test data cannot be provided.
Color: sky blue, very characteristic, that has become a standard color ---- turquoise.The rest have dark blue, light blue, lake blue, blue green, apple green, yellow green, light yellow, light gray.Copper causes the blue color, iron substitutes part of aluminum in the chemical composition, giving turquoise its green color, and water content also affects the blue hue.
Absorption spectrum: under strong reflected light, two moderate to faint blue bands of 432 nm and 420 nm can be seen occasionally, and sometimes ambiguous bands can be seen at 460 nm.
Luminescence: in the ultraviolet long irradiation has light yellow green to blue fluorescence, short wave fluorescence is not obvious.There was no obvious luminescence under X - ray irradiation.
Thermal properties: turquoise is a kind of non-heat-resistant jade, heat will usually burst into fragments, brown, green under the flame.Drying and discoloration can also occur in the presence of sunlight.
Acid: Dissolves slowly in hydrochloric acid.
Turquoise pore development, so the identification process, turquoise should not be in contact with the colored solution, in order to prevent the colored solution will be polluted.
Place of origin
China is one of the major producers of turquoise.Hubei, shaanxi, yunxi county, anhui ma on shan, zhushan county villagers were ulam baihe, henan xichuan, hami, xinjiang, qinghai and other places have a turquoise output, of which hubei yunxian county, YunXi, zhushan high quality turquoise as world famous around the origin, the cloud covered the mountain turquoise of cloud cover to the top of the mountain temple named cloud cover temple turquoise, is the world famous Chinese stone carving art of the original stone producing area,It enjoys a good reputation in the industry and the collection circle and sells well at home and abroad.In addition.Turquoise is also found in Jiangsu, Yunnan and other places.
Iran, the famous turquoise producing area abroad, produces the best quality porcelain pine and iron pine, known as Persian turquoise.Turquoise is also produced in Egypt, the United States, Mexico, Afghanistan, India and the former Soviet Union.
Maintenance
Turquoise, like other items you cherish, need to cherish and maintain, otherwise in the process of use, will change from clean to dirty, from light to dark, from new to old.
Most turquoise have hole, wipe my hands can absorb oil, embellish lipstick and perfume, etc., while in our country's traditional process, can give a turquoise surface coated with a layer of wax, in order to increase the turquoise color, at the same time also have played an important role in protection of turquoise, but still should be paid attention to when wearing HanJi, oil, etc., avoid contact with cosmetics and skin grease too much, so as not to damage the gems.Because turquoise porous, pay attention to avoid using heavy liquid density identification, because three bromide methane, methane iodide will make turquoise discoloration.Turquoise color is delicate, afraid of pollution, should avoid contact with tea, soapy water, oil, rust and alcohol, in order to prevent the infiltration of gem color along the pores.
Turquoise is afraid of high temperature, cannot bake with direct fire and sunlight, lest fade, blast crack, dry crack.Long time of large sun exposure will make the turquoise due to water loss and crack and fade, high temperature baking will make the turquoise brittle broken.Some Indian handmade jewelry is beautifully made and expensive to repair.However, the thermal conductivity of silver is very high. When repairing silver jewelry, the temperature is difficult to control, and the turquoise inlaid on it will be broken because of the high temperature.Because the stones are bonded to a metal material.
Turquoise hardness is not big, in the wear of preservation should avoid and other hard jewelry or items collision.Do not put the turquoise into the ultrasonic cleaning machine, on the one hand, the turquoise with holes will absorb the solution to discolor themselves;On the other hand, due to contact with other jewelry during ultrasonic vibration, the turquoise surface, whether porous or dense, may be damaged.