Qicaishi

Have you ever seen a stone as beautiful as a rainbow? Maybe most people haven't seen it. Because this kind of stone is very rare. As far as I know, in China, only Hubei Huangshi and Guizhou produce colored stones. Especially the colored stones in Huangshi are better.

Yellowstone colored stones occur in the oxidation zone of polymetallic deposits dominated by copper and iron, and often coexist with calcite, limestone, dolomite and quartz. Looking around, it is densely attached to the scrawny stone body, with tiny crystals as big as pepper seeds and fish seeds, which are crystal clear and colorful, dazzling. Her strange brilliance is easy to remind people of rainbows after rain. Why are the colored stones in Huangshi so beautiful? It turns out that Huangshi is known as the "cornucopia of the south of the Yangtze River" and is extremely rich in mineral resources. Ferrous metals include iron and manganese, nonferrous metals include copper, tungsten, molybdenum, zinc, lead, cobalt and nickel, precious metals include gold and silver, and rare elements include germanium, gallium, thallium, indium, selenium, strontium, rhenium and tellurium. Most of the mineral deposits in Huangshi are polymetallic. A series of chemical changes will take place in the part near the surface under the action of external factors such as sun and rain, and colorful and beautiful colors are the result of this long-term change. The more metallic and nonmetallic components are contained in the ore, the richer and brighter its color is. According to the determination, the specific gravity of Huangshi colorful stone is 3.3-4, and the hardness varies with the mineral composition, and the highest is 5-6.

It should be noted that the production of colored stones in Huangshi is not much. Only at the end of last century did some mines produce this kind of stone. Because of its high ornamental value, collectors from Hong Kong, Macao and Taiwan and European and American countries are ecstatic and buy in large quantities. Now this kind of ornamental stone is rare in the local area, and can only be found on the antique shelves of some stone appreciators.

Tourmaline is tourmaline, and its English name comes from the ancient Sinhalese word Turmali, which means "mixed gem". Legend has it that tourmaline originated in 1703. Several children in Amsterdam, the Netherlands, played with stones brought back by Dutch sailors and found that these stones not only have strange colors in the sun, but also have the power to attract or repel light objects. Therefore, the Dutch call him a stone sucker. It was not until 1768 that the famous Swedish scientist Ringnes discovered that tourmaline also has piezoelectricity and pyroelectricity, which is the origin of the name tourmaline. Up to now, tourmaline is commonly used in science to measure the change of luminous intensity and pressure. At the beginning of World War II, it was the only substance that could judge the pressure of nuclear explosion. Now, it is widely used in the optical industry.

In China, the word tourmaline first appeared in the classic "Shiya" in Qing Dynasty: "The name of Biya Yao was recorded in China, but it was not detailed. The Qing Dynasty canon says: Do concubines use Biya Ding? Yunnan people say: than easy to thank, than easy; Uji is also Bixia Creek. Everyone in this world is called Biya, or Bibi, but there is no question about the origin of this name. If it is a foreign dialect, there is no doubt. " In later historical documents, we can also find names such as arsenic, tourmaline, bixiaxi, and broken evil gold. Tourmaline is the common name of our jewelry industry. Legend has it that tourmaline is also the favorite of Empress Dowager Cixi. According to historical records, in the funeral of Empress Dowager Cixi in the Qing Dynasty, there was a lotus carved by tourmaline, weighing 3,628 yuan (about 5,092 grams), and a pillow made of watermelon tourmaline, which was worth 752,000 silver at that time.

In addition, in Japan, some Japanese institutions believe that tourmaline is very popular in Japan, because it has pyroelectricity (meaning that it will generate charges at the two poles when the temperature changes) and piezoelectricity (pressing the C-axis direction of tourmaline will generate charges at the two poles), so it can produce magical curative effects and improve natural healing power.

[Edit this paragraph] Types of tourmaline

For gemstones, tourmaline is the name of a group, but under the classification of GIA (Gemo Logic Institute, USA), tourmaline can be divided into:

Ruby, emerald, indigo, biotite, Sibelli, beryl, bicolor, watermelon, cat's eye. Fourteen kinds of tourmalines, such as tourmaline, alexandrite tourmaline, hectorite tourmaline, chrome tourmaline and Paraiba tourmaline.

Almost all tourmalines with gem-grade value are produced from pegmatite granite, and tourmalines are widely distributed. However, most of the tourmalines on the market now come from Brazil, and some are from Tanzania, Kenya, Madagascar, Mozambique, Namibia, Afghanistan, Pakistan, Sri Lanka, Italy, California and Myanmar, and even Xinjiang and Yunnan in Chinese mainland.

It is said that tourmaline crystals have as many as 15 colors, mainly colorless, rose red, pink, red, blue, green, yellow, brown and black. Among them, the top grade is transparent and shiny blue, fresh rose red and pink plus green composite color. Tourmaline has been loved by people since ancient times because of its bright color, variety and high transparency. Tourmaline is one of colored gems after diamonds, rubies, sapphires and emeralds. The appearance of tourmaline, like other precious stones, is based on color luster, transparency, inclusions, defects and weight. However, due to the brittleness of tourmaline, attention should be paid to avoid collision when wearing it.

At present, the price of tourmaline in Paraiba is the highest. This special neon-red-blue-green gemstone was first discovered in 1989 in San Jose de Baatar, a small village in Paraiba, Brazil. Because of its difficulty in mining, small crystal and unclear mineral rights, disputes have continued in recent years and the price has remained high, especially in Japan. The retail price of high-grade tourmaline can reach $20 thousand per carat. Recently, a new Paraiba tourmaline mine was discovered in Parejas, Rio Grande do Norte, about 40 kilometers away from the old mine in Brazil, so the price soared again at the urging of the market. As for the tourmaline market in Taiwan Province Province, red and green (commonly known as watermelon tourmaline) are still the best sellers. Among them, the red tourmaline produced in Nigeria is the best-selling commodity in the market; Tanzanian tourmaline contains chrome green, which is as bright as emerald and is also very popular.

[Edit this paragraph] The Spirituality of Tourmaline

Tourmaline is a general term for all tourmalines. Because tourmaline has a variety of bright colors, it is easy to make people feel happy, advocate freedom, and broaden their minds and horizons.

Tourmaline can also stimulate creativity, bring endless inspiration and thoughts, calm, clear and concentrated power, make you act properly and go all out, and radiate the frequency of attracting love and friendship.

Tourmaline can also radiate an affinity magnetic field, which naturally attracts more people to your side and melts the gap between people.

Tourmaline itself has a high effect on metabolism and endocrine activities, and it can balance the internal gas field, make the elements of yin and yang opposite easy to combine and merge, and also resolve various conflicts and contradictions between people externally.

Mental functions of different tourmalines;

1, black tourmaline: Black tourmaline has a dark appearance.

(1) can effectively eliminate stress, fatigue and polluted air, and improve health and luck.

(2) For people who are easily frightened and have nightmares at night, placing black tourmaline can stabilize the space energy field and ward off evil spirits.

(3) It helps to protect patients from external interference, concentrate on recovering from illness, and enhance the recovery speed.

2, blue tourmaline: blue tourmaline, corresponding to the throat wheel and the third eye, the main communication and sensitivity.

(1) can effectively enhance communication, expression and persuasion.

(2) For people who are too generous, generous and enthusiastic, they are easy to be used by others and suffer losses. Wearing blue tourmaline can balance this personality.

3, green tourmaline: green tourmaline corresponds to the heart chakra, is a gem that can make people happy, happy and satisfied, also known as the stone of wealth.

(1) Green light is the light of wealth, which can make people feel happy and make money.

(2) The green light is easy to make good friends, have a good relationship and good luck, and it is also easy to get the appreciation of the boss and the help of the nobles.

(3) It can help to eliminate troubles, depression and unhappiness in the heart and bring real happiness and joy, especially for people with depression, autism or easy self-denial.

(4) For those who are weak, unwilling and unwilling to do things, it is helpful to find the joy of work, and they are willing to devote themselves and go all out to obtain self-realization satisfaction.

4. Rose tourmaline: The red hue of tourmaline is widely distributed, mostly between powder and powder, with a few deep red ruby-like colors. Its energy makes people warm, unrestrained, cheerful and comfortable, corresponding to the heart chakra, which is extremely pleasant.

(1) Sending a rose tourmaline to the opposite sex is a good way to express your love and win the other person's heart. Wearing rose tourmaline is also easy to attract wonderful love and ideal partner; Or make the feelings between husband and wife stronger.

(2) When others are biased against you, it helps to improve the relationship between them; When you are indifferent to others, you can enhance their popularity; At the same time, it helps to eliminate a person's inner indifference, aloof, withdrawn and all kinds of abnormal psychology, making people easy to get along with.

(3) For people who often need to deal with the public or work, it helps to spread personal charm and strengthen leadership temperament, which will naturally attract more people and gain people's support.

(4) For women who love beauty, it is said that beauty also plays a role.

5. Watermelon tourmaline: Watermelon tourmaline is in a spar, which has the characteristics of blue-green infrared and looks like a watermelon-like tourmaline. Because of its name, the number is scarce, so it is more expensive; It is said that the watermelon tourmaline was placed under the pillow where Empress Dowager Cixi slept.

(1) helps to eliminate all conflicts, contradictions and complicated feelings in the heart, and makes people have a happy and joyful mood.

(2) People in complex relationships, interest disputes or emotional conflicts will help to resolve myths and see the truth clearly; For men and women who are affectionate, promiscuous and often have emotional entanglements, it is helpful to get rid of multi-party relationships, so that they can feel at ease and find true love.

(3) Public relations personnel, salesmen, shop assistants and receptionists wear watermelon tourmaline, which is helpful for being well-proportioned and versatile, and is easy to promote business. It can strengthen communication and coordination, handle complex situations and get a satisfactory result.

[Edit this paragraph] Tourmaline is introduced in detail

Tourmaline has a short history as a gem, but because of its bright and rich colors and high transparency, it won people's love as soon as it came out, and it is called a gem with a variety of customs. There are many tourmaline ornaments in the imperial palace of the Qing Dynasty in China. Tourmaline is a popular mid-range gem variety at present, and is known as the birthstone of October.

Tourmaline is a compound borosilicate characterized by containing B, and its chemical molecular formula is (Ca, K, Na) (Al, Fe, Li, Mg, Mn) 3 (Al, Cr, Fe, V).

6(BO3)3(Si6O 18)(OH，F)4。

Tourmaline is a common phenomenon of two-color zoning, which can be parallel to the bottom of the crystal or form an annular zone parallel to the cylinder.

Transparency and luster of tourmaline: transparent-translucent-opaque, glass luster.

Optical characteristics: uniaxial crystal, negative optics.

Luminescence: generally no fluorescence, pink tourmaline has weak red to purple fluorescence under long and short wavelength ultraviolet light.

Optical effect: tourmaline containing a large number of parallel fibers or linear hollow tubes can show cat's eye effect after being cut into arc gems. Because of the thick tubular inclusions, the cat's eye effect is usually poor.

mechanical character

(1) cleavage fracture: no cleavage, shell fracture. The cross section is a spherical triangle.

(2) Hardness: 7-8.

(3) Relative density: 3.06 (0.20, -0.60).

Introduction of Tourmaline with Different Colors

1, red tourmaline

Because it contains manganese, it is red to pink, with obvious polychromatic color and red to pink. The highest value is tourmaline, which is called "double pink" by the business community.

2. Blue tourmaline

Because of iron, it is blue, and multicolor is from obvious to weak, showing dark blue and light blue.

3. Green tourmaline

Because it contains chromium and vanadium, it is green, with obvious multicolor, light green and dark green. The birefringence is high, usually 0.0 18, and the highest is 0.039.

4. Brown tourmaline

Mostly magnesium tourmaline, with obvious polychromatic color, ranging from dark brown to green brown.

5. Two-color tourmaline

Ribbons (bicolor, tricolor and multicolor) often distributed along the long axis of the crystal, or concentric ribbons, are usually called "watermelon tourmaline" when the infrared is green.

The quality of tourmaline can be carried out from the aspects of weight, color, clarity and cutting.

1, color

Rose, purple, green and pure blue are the best, followed by pink, yellow and colorless.

Step 2 be clear

It requires as few internal defects as possible, and the crystal clear tourmaline has the highest price. Tourmaline contains many cracks and gas-liquid inclusions, and is usually used as jade carving material.

3. Weight

The greater the weight, the higher the price.

4, cutting work

Cutting should be regular, proportional and well polished. Otherwise, it will affect the value.

Tourmaline, like most crystals, will have a better luster after being worn, and the crystal will be more transparent. Generally, there will be obvious changes in a short time, so the newly bought tourmaline of the same grade will not be as beautiful as tourmaline for a while.

The choice of tourmaline: tourmaline often appears in places where crystals are sold, and many people think it is crystal! Actually, it is a gem, and it is a fine gem.

Its color is easy to distinguish, mainly depending on the overall clarity and cotton content. The color is good, transparent and especially bright, which makes you feel like you are oiled!

No gem has such rich color changes as tourmaline. From the Mediterranean region with a long history, as early as AD 1703, the Dutch began to import tourmaline from Sri Lanka to Europe. They named this newly discovered ore Ceylon Tufamall, but the original intention is unknown.

Pure monochromatic tourmaline (monochromatic) is very rare. Most crystals have multiple shades or even completely different colors, and usually the colors are displayed in layers. Brazil produces a kind of tourmaline with red inner layer, white inner layer and green outer layer. The tourmaline in South Africa is green inside and red outside. If the inner ring of a tourmaline is red and the outer ring is green, it is called "watermelon tourmaline". These color matching and color changes can be clearly observed after the section of the slice is polished.

Cat's eye tourmaline also exists in many colors, but only pink and green varieties will have strong Chatoyancy, which is due to the inclusion of foreign crystals. Some tourmalines also show slight color changes under artificial light sources.

After heating and subsequent cooling, or applying pressure, or rubbing with silk or wool in dry weather, tourmaline crystals will become charged. In the direction perpendicular to the C axis, one end will generate positive static electricity, and the other end will generate negative static electricity, which will attract some dust particles and even small pieces of paper. This is the piezoelectricity of tourmaline, which is currently used to measure the pressure caused by explosion in air or water. The first Dutchman who introduced tourmaline to Europe already knew this effect. They used a heat-treated tourmaline to suck ash from their sepiolite pipe and called it "aschentrekker" (meaning a tool similar to smoking ash).

Tourmaline deposits are usually located in pegmatite and alluvial deposits. Apart from Sri Lanka and Madagascar, Brazil has the highest output. Brazil produces red, green and blue tourmalines. Recently, a special tourmaline named "Paraiba" has been discovered. Its color is different from other gems. It is green with blue, like lake green, and its color is beautiful and special. However, due to the scarcity of production and the high price, it is deeply loved by the Japanese. Mozambique supplies high-quality red and two-color tourmaline. More mineral deposits are distributed in Angola, Australia, Myanmar (red tourmaline), India, Rhodesia (New Guinea), Namibia, Tanzania, Thailand, Russia (especially in Wulashan and Caucasus, there are purple, red and blue tourmalines) and the United States (California is most famous for red tourmaline, while Maine is red, green and watermelon tourmaline. As for Europe, collectors have found tourmaline in Elba and Switzerland. In addition, tourmaline was introduced to China in the Qing Dynasty, and it was mostly used as a decorative gem on the top of the hats of first-class or second-class officials.

Pink, bright red and green are the most demanding colors, among which red and green tourmalines are the most common and popular, but only the colors with medium depth and bright degree are the best. If the color is too dark or too light, the value will be greatly reduced. Green tourmaline containing chromium is rarer than red tourmaline, and its price is slightly higher. Tourmaline containing chromium will turn red when tested by color filter. Because tourmaline has a strong multicolor, it must be cut. Usually the section is parallel to the spindle center C, but for light tourmaline, in order to get deeper color, the section should be perpendicular to the spindle center C, because tourmaline is dark in the direction perpendicular to the C axis and light in the direction parallel to the C axis.

When heated to about 842-1202/450-650℃, the color of tourmaline will change slightly: green tourmaline will turn into turquoise, and reddish brown tourmaline will turn into fiery red. Generally speaking, no synthetic tourmaline has been commercialized. Because of its rich and varied colors, tourmaline is often confused with other natural gems. Especially amethyst, andalusite, chrysoberyl, topaz, garnet, emerald, olivine, smoky Shi Ying, ruby and emerald. Synthetic green spinel, pink topaz, idocrase, zircon and some glass imitations. The important identification marks of tourmaline are its high birefringence and strong polychromatic color. Ruby and opal are birthday stones in October.

[Edit this paragraph] Tourmaline purchase

Pay attention to the following aspects:

1, transparent. Tourmaline requires crystal clear, the more transparent, the better the quality, and there is no obvious fog or opacity.

2. color. Tourmaline is more precious among red, blue and green. In the choice of tourmaline jewelry, red, blue and green are the best, and the colors are required to be uniform and gorgeous; Among necklaces and bracelets, it is best to have rich colors. The color of each bead can be different, including red, yellow, blue, green and purple. Tourmaline is rich in color, and two or more colors appear on the same tourmaline, that is, two-color tourmaline or multi-color tourmaline, and the watermelon tourmaline with infrared green inside is also more precious; In addition, tourmaline cat's eye belongs to the top grade of tourmaline.

3. purity. Tourmaline is fragile and prone to cracks. It also contains a lot of inclusions. The existence of a large number of cracks and inclusions will affect the transparency, color and fire color of tourmaline, and the tourmaline with very pure interior is also rare and belongs to the top grade. When choosing, try to choose the one that is clean inside.

[Edit this paragraph] Identification and evaluation of tourmaline

Identification of tourmaline

Tourmaline is a composite silicate with Mohs hardness of 7-7.5, specific gravity of 2.9-3.2 and refractive index of 1.624- 1.644. In general, tourmaline raw materials are long columns with longitudinal stripes on the cylinder and curved triangles on the cross section of the crystal, so the raw materials are easy to identify.

The identification of tourmaline ornaments can be mainly based on the following three characteristics: first, tourmaline has a strong dichroism, and red tourmaline is red and pink; Green tourmaline is green. Green. Based on this, green tourmaline can be distinguished from olivine, green glass and green garnet. Secondly, tourmaline has a large birefringence. From the stage, there is obvious ghost phenomenon at the bottom, so tourmaline can be distinguished from topaz and synthetic spinel. Thirdly, tourmaline is often ground into emerald, and some tubular wraps or cotton wool can often be seen in the parallel long direction, but its color is often found to be darker in the short direction. This is because tourmaline absorbs different light in different directions, and some synthetic imitations can be distinguished by this characteristic.

Similar to tourmaline are andalusite and diopside. It is still difficult for the naked eye to distinguish these gems, and it is necessary to use refractometers, heavy liquids and other means.

The key to identification is to remember that the long column and cross section of tourmaline are curved triangles; It often has obvious dichroism and can be seen as double shadow.

Evaluation of tourmaline

The price of tourmaline is mainly restricted by its color. In the international market, bright red and bright blue tourmalines are generally the highest in price, while red and green tourmalines and rose and emerald tourmalines are also very popular in the market with higher prices.