1. chemical composition: sodium aluminum silicate-aina [si2o6], which often contains trace elements such as calcium, chromium, nickel, manganese, magnesium and iron. CASNo.: 1344-00-9.
2. Mineral composition: jadeite is the main mineral, followed by omphacite, cristobalite, aegirine, amphibole and albite. Jade flower piece
3. Crystallization characteristics: monoclinic system, usually columnar, fibrous and felt-like dense aggregate, with massive raw materials and gravel-like secondary raw materials.
4. Hardness: 6.5-7.5
5. Cleavage: fine aggregate has no cleavage; Glittering "fly wings" can be seen on the section of coarse particles.
6. Gloss: grease luster to glass luster
7. Transparency: translucent to opaque
8. Relative density: 3.30-3.36, generally 3.33.
9. Refractive index: 1.65—— 1.67, and there is a fuzzy shadow boundary near 1.66 on the refractometer.
10. color: colorful, among which green is the top grade, which can be divided into three types according to color; (1), leather color; Refers to the color of the outermost epidermis of jadeite, and its formation is related to the later weathering. This color is red, yellow and gray with different shades, and it is characterized by being nearly concentric near the skin of raw materials. Red is often called fee; 2. Ground color: also known as "ground color", it refers to ground color and other colors other than green, such as different shades of white, oil paint, lotus root starch, gray, etc. 3. green; Refers to the true color of jadeite, which shows various shades of green. Sometimes green contains black. Green is usually called emerald.
1 1. Luminescence: light-colored jadeite emits dim white fluorescence under long-wave ultraviolet light, but has no response under short-wave ultraviolet light.
Based on the relevant data, this paper briefly introduces the production of Myanmar rough stone for reference:
One: The factory is new, with no skin, good water and white fog. It mainly produces violets and Hong Fei.
Two: Pagang is a famous historical pit, which was first mined. Pagan skin is thin, mainly gray and yellow-white, with fine crystals, good seeds, high transparency and sufficient color.
Three: the gray card shell is mottled, mainly gray green and gray black, with different transparency and uneven distribution at the bottom, but the water is often better where there is green.
Four: Ma Meng, also known as Wusha Black Wusha, is gray in black, and the bottom of the water is generally poor, often with black silk or white fog, and blue in green. Five: wood chopping, also known as knife grinding, is mostly brown-gray, yellow-red, generally good and low in water, but mostly white and yellow fog. Six: the skin of the plaster is thick and the skin color is grayish yellow or gray; The water and bottom are good, and there are few cracks. It is a green or all-green high-green variety with few impurities. Glass bottom is more common, but the output is less.
Seven: Self-wall, also known as inferior leather shell, is mainly yellow-gray, with good bottom and few cracks, but there is white fog, and its products are famous for their good blue flower water.
Eight: Longtang, also known as Longkeng, is mainly made of yellow sand skin or gray fish skin, and the skin shell is thick. Most of the water and the bottom are good, the green is very positive, and high-quality materials are often produced.
Nine: Martha is a new factory, with no skin or less skin, light green, good water quality and poor bottom, which is mainly used as low-grade Burmese jade bracelet material or large decorative material.
Ten: Houjiang River, also known as Lingdi, is divided into old Houjiang River and new Houjiang River, both of which are produced in bed impact sand. Among them, Laohoujiang is produced at the bottom of the impact layer.
There are some terms to evaluate jadeite, such as "land", "good water" and "good jadeite". "Land" refers to other colors in jadeite, and jadeite is mostly top grade; "Good water" means that jade is tender and smooth, transparent and clear, glittering and translucent and dignified, bright and gratifying, also known as Yuhuan.
Called "Joe", which in turn is called "water difference"; "Good Cui" should combine the words "strong, positive and harmonious". "Strong" means strong but not weak, such as holly after rain, "positive" means bright, "positive" means no variegated colors and evil spirits, "harmonious" means even green, and vice versa.
Economic evaluation factors
1. Transparency: translucent is the best, but too transparent or opaque is not good.
2. Structure: The finer the particles, the better.
3. clarity: the best without flaws.
4. Cutting: the design of "cutting the jade without cutting the abrasive", finely crafted modeling, polishing and novel styles.
grade
(1) Super grade: bright green (emerald), apple green, glass floor (translucent, fine texture), even and bright, without impurities and cracks.
Commodity grade: green, oily green land, slightly transparent, translucent grandmother green veinlets and mottled green.
③ Ordinary grade: lotus root powder mill, bean green, light green, fine white and slightly transparent. Opaque jadeite is generally only used as jade ornaments.
classify
A permission: wax dipping treatment.
Product A of jadeite is natural jadeite, which refers to jadeite that is naturally produced, not artificially destroyed by physical and chemical methods, or brought in and out by substances. Jade that has been decontaminated by weak acid and weak alkali and waxed by traditional technology is also A goods. -that is to say, the artificially colored jadeite has not been soaked in strong acid.
The bleached and polymer-embossed jade was treated by pickling, bleaching and glue injection.
C goods (coated jadeite) dyeing treatment. Used for jadeite dyeing. Whether it is acid leaching bleaching or filling with glue, artificially colored jadeite is called C goods.
Difference assessment
Put the jade under the fluorescent lamp and observe its color change. Goods A and C are unchanged, and goods B are fluorescent white. C goods are dyed, so their colors are uneven along the cracks, which can be seen with the naked eye.
estimate
Color is the first factor to evaluate jadeite, and the standards of good color are: intensity, sunshine, positivity and harmony.
Positive: refers to the range of hue, which depends on the ratio of primary color to secondary color, that is to say, it should be pure green and not mixed with other colors. For example, oil blue is often mixed with oil blue, and its value will be reduced.
Thick: refers to the depth of color. As far as emerald green is concerned, the concentration is preferably between 70% and 80%, and 90% is too strong. Yang: It refers to the lightness of jade color. The lightness of jade is mainly determined by the ratio of green to black or gray. The more green, the brighter the color. The more black or gray, the darker the color. Experts often use an image method to express the bright sunshine of color. For example, boxwood green, parrot green, onion heart green and pepper green all refer to the color of fresh sun. Spinach green, oil green, river green and dark green refer to dull dark green. The fresher the jadeite, the higher its natural value.
Average: refers to the uniformity of jade color distribution. The color distribution of jadeite is generally uneven, so it is not easy to get jadeite with uniform color distribution.
The best color: it should be pure green with a green concentration of 70%-80%, bright sunshine and uniform color distribution. This kind of high-grade jadeite habit is called the old pit species by experts.
appraisal of quality
1 texture. Natural jadeite is transparent or translucent in texture, and its surface is bright and shiny. If you look closely, you can see the nearly round and slightly transparent "salt particles" and the fibrous substances around them.
② Hardness. Natural jadeite is jadeite, and its Mohs hardness is 7 degrees. It will be carved by a sharp knife without leaving any trace. The hardness of fake jade is low, so a sharp knife can draw it out.
3 Emerald. When natural jadeite is observed under strong light, emeralds with other mineral particles can be seen, which are called Cui Hua or emeralds. Fakes made of glass, plastic and porcelain have no such "emerald" characteristics.
④ Relative density (specific gravity). Natural jadeite has a hard and dense structure, no bubbles, high density and crisp sound when it is knocked; Fake products have loose structure or bubbles, low density and hoarse knocking sound.
⑤ color. The real product is rich and pure emerald color. Some fakes are made of white jade, serpentine, Australian jade, Han Guoyu, marble and even various stones. After decoloring, it is filled with high-hardness plastic slurry and colored, or soaked in green liquid to make "colorful jade". Observing under strong light, you can see green lines, which are messy and small; Some do not show lines, but they are not clear, with poor gloss and lighter weight than the real thing.
Put the fake into the melted wax liquid, and the injected pigment will slowly separate out. In this way, the detected sample will not be destroyed, and the authenticity can also be identified.
Observed by Charles filter, the colored emeralds are purplish red under the mirror, and the natural and authentic colors remain unchanged.
Some fake jadeites are artificially melted by glass, with loose structure, uniform and dark green color, some with bubbles, and hoarse when struck with hard instruments.
Fake jade: Ma Laiyu (Emerald) is as transparent, green and beautiful as high-grade jade. But it's not hard to identify. Looking at it with a magnifying glass under strong light, there are fishnet-like patterns inside. The mesh of fishing net is green, and the mesh is white, unlike the green in jade, which is uneven in size and shape.
Selection and purchase
1 Look at the color. See if the color is pure, rich and uniform, and use a spotlight flashlight to check whether there are hidden variegated colors. Rich, pure and uniform color, less impurities. Emerald green has a higher price, followed by red and purple. Among the greens, tender and yellowish Mabel Miao (also called "Yang Miao" green) with three parts of water is the best, followed by emerald green, river green and oil green, which are evenly distributed.
② Observe the transparency. Observing under strong light, the higher the transparency, the better.
3 Listen to the sound. The knock on the door is crisp and pleasant.
④ Observe emeralds and stone flowers. According to light observation, jadeite has the flash of other mineral particles (namely emerald), and there are often massive white flowers called stone flowers. Both of them get twice the result with half the effort.
⑤ Look at cracks and dark spots. Some cracks exist in the raw ore, and some are caused by processing, so the less the better; Black spots are everywhere in jadeite, so it is better to have fewer and smaller ones.
⑥ Look at the processing level. Smooth surface, good polishing and good shape are preferred.
Generally speaking, the investment value of ordinary jadeite is not high, and only high-grade jadeite can gain huge value-added space, but high-grade collection-grade jadeite is less than one tenth of all jadeite, so it needs professional knowledge and vision to find fine products from the dazzling jade market.
Look at the transparency of its texture first. Generally speaking, jadeite is transparent or transparent, and experts call it "old jade", which has the highest value. Translucent jade is called "new and old species", followed by price. Jade is opaque, and the dried jade is called "new kind of jade", which has low value.
The second is to look at the color. Jade is rich in colors, such as green, red, purple, gray, yellow and white, among which green is the most precious. According to the depth of green, it is divided into many kinds, such as ruby green, brilliant green and glass green 10. High-quality jadeite is green, rich, transparent, oily and free of impurities. When struck with a hard instrument, the sound is crisp and loud.
Tips for Appreciation and Purchase of Jade Articles
First, it depends on its texture. Choose a transparent one. Through the light, you can see that jadeite has some fog or spots, but glass imitations do not have these characteristics. No matter how well this imitation is done, there will be bubbles.
Second, jadeite has a high hardness. The hardness of jadeite is incomparable with other jadeite and glass. Jade can scratch glass, and it is doubtful that it can scratch any trace.
Third, jade is heavy, and it feels heavy in your hand, while glass imitation is relatively light.
Fourth, look at the workmanship. It's best to look at it more than four times with a magnifying glass.
Fifth, shop around and compare prices.
The quality of jadeite should be observed from four aspects: color, transparency, shape and whether there are impurities.
The color must be positive, rich and uniform, with good transparency and delicate texture.
The shape, size and thickness of jadeite should be appropriate and finely ground.
Emerald land and emerald green are interdependent and closely related. Generally speaking, when the green water is good, the land is usually not too bad, and vice versa. The motto is mainly to remind people not to ignore the particularity of emerald green. Although not every "shit place" will have advanced green. But "shit" can appear in the first class.
Selection and valuation principles
The first grade jadeite is called jadeite. Color, transparency, uniformity, shape and tapping are the methods for ordinary people to appreciate or evaluate jadeite. Jadeite can be divided into: glass type, dark pit, old pit, gold wire, oil clear, bean green, flower green and melon green. Among them, the jadeite with glass species is the top grade, and the one with extra high moisture and good transparency is also called "ice species", which can be said to be a treasure among "glass species". Most consumers who buy jade bracelets may have this experience, that is, merchants will knock the jade bracelet on your face to see if its sound is crisp and clear, preferably crisp and melodious. This is to prove that the crystal of jade is dense, the texture is good and there is no crack.
1. emerald green: the more tender the green, the more valuable it is.
2. Transparency: The jadeite crystal structure is compact and the transparency is high. What we call "glass seed" is this kind of jadeite with high transparency. For example, because jade itself is rich in chromium, it is valuable and hard to find to form ice jadeite.
3. Uniform color: In addition to green and tender color and high transparency, it must be uniform to be the top grade.
4. Defects: Pay attention to whether there are cracks and spots, which will affect the quality of jadeite.
5. Shape: Most jadeite rings are oval, but there are many other shapes. The shape and beauty also have an impact on the price of jadeite.
6. Carver: The quality of the work and the symbolic meaning of the ornaments have an impact on the price.
7. Size and thickness: Of course, jade of the same quality, big and thick, is expensive.
8. Gloss: In addition to the above conditions, the gloss should be bright and not dark.