A carved gem
Refers to the kind of stone or mineral that can meet the requirements of jewelry after grinding and polishing.
The identification of gems can generally be divided into two categories: rough stones and finished products.
The identification of the original stone can be divided into field identification and indoor identification. In the field identification, most simple tools such as magnifying glass and knife are used to preliminarily name gem minerals. Indoor identification mainly uses various means and instruments to further determine the data of gem minerals, which provides an important basis for gem identification.
For the identification of finished gemstones, it is necessary to identify the tested gemstones without destroying the integrity of the gemstones.
At present, the commonly used and easy-to-master gem identification instruments are as follows:
1. Pen spotlight flashlight: used to observe the transparency of dark gemstones. Beads of spotlight flashlight should be concave in the writing surface, not protruding from the writing surface, otherwise it is not easy to observe.
2. Magnifier: It is one of the instruments for magnifying and observing gems. The most commonly used magnifying glass is 10 times, and there are several kinds of magnifying glasses with 20 or 30 times. Magnifier is a key tool and necessary thing for gemologists, and it is easy to carry. It can be used to identify the variety and authenticity of precious stones. With a magnifying glass, we can observe: (1) the surface damage, scratches and flaws of the gem. (2) Cutting quality. (3) Polishing quality. (4) Defects and inclusions in gems. (5) color distribution and growth line. During identification, the gem should be placed under strong light about 2.5 cm away from 10 times the magnifying glass, and the distance should be adjusted slowly until it is clear. It is also important to choose the quality of the magnifying glass. Poor quality amplification will produce graphic distortion.
3. Dichroic mirror: Some gems are multicolored, and the best instrument to observe the multicolor of gems is the dichroic mirror. Dichroic mirror is a kind of optical instrument with reasonable structure, low price, compact and simple. The dichroic mirror uses a suitable transparent colorless calcite (Iceland spar) diamond. Because Iceland spar has high birefringence, the instrument can separate two plane polarized light rays passing through the gem. It is required that single crystal gemstones with transparent colors can detect polychromatic colors, while jadeite cannot detect polychromatic colors. Dichroic mirror is mainly used to distinguish ruby from spinel and red-purple tooth black; Distinguish blue spinel from blue tourmaline; Distinguish sapphire from blue synthetic spinel. When detecting a gem with a dichroic mirror, you must keep turning the gem until the two colors with the biggest difference appear on the window. For the determination of trichromaticity of gemstones, we must carefully and repeatedly test. Seen from three different directions, three colors seem to be three colors. Note during testing: the distance between eyes, dichroic mirror and gem sample should not exceed 2-5mm.
4. Refractometer: Refractive index is an important optical constant of transparent gemstones and the main basis for identifying gemstones. There are two main methods to measure refractive index: one is direct measurement and the other is refractometer measurement; The other is relative measurement, which cannot be immersed in liquid. Refractometer is made according to the principle of total reflection of light. At present, the commonly used refractometer is only suitable for gems with refractive index of 1.36- 1.8 1. The calculation method of the refractive index (n) of gemstones is that the ratio of the propagation speed of light in air (V 1) to that in gemstones (V2) is a constant, that is, N=V 1 /V2. An isotropic gem in which light propagates with constant propagation speed and equal refractive index is called single refractive index. Anisotropic gemstones have two readings in the refractometer, and the difference between the maximum and minimum refractive index values is called birefringence. Refractometer is one of the most commonly used instruments for gemologists. It is small in size and convenient to use. He can not only measure the refractive index of faceted gemstones, but also measure the refractive index of globoidal gemstones through point measurement.
5. Charles color filter: The color filter is designed by using the specific wavelength of absorbed light. It consists of two gelatin filters that only let dark red and yellow-green light pass through, and it is a gem identification instrument. The color filter is small in size, light in weight, and easy to carry, which is particularly effective in identifying some dyed gems and artificial gem, and is very effective in identifying colored jadeite. It can distinguish emeralds from other imitations, and it must be comprehensively considered by other methods in order to judge accurately. Emerald appears red or pink under the color filter, while other natural green gems similar to emerald do not appear red under the color filter.
6. Gem microscope: an important tool for magnifying and observing gems. It can detect the external and internal features of gems that cannot be clearly confirmed or observed with a magnifying glass of 10 times. Gem microscope can observe the inclusions, cleavage, twin lines, growth lines and color bands inside the gem; Observe the grinding, polishing degree and accidental damage of gems; Distinguish between two-layer stones and three-layer stones that assemble gems. Gem microscope has reasonable structure, complete auxiliary equipment and large variable magnification, which is generally 10 to 70 times. Gem microscope has two kinds of light sources. Generally, the bottom lamp is used to observe the internal defects of gems, such as inclusions and cracks. Observe the surface features of gems, such as cracks, bands and cleavage planes. , with reflective lights. Gem microscope is a precision instrument and should be used in strict accordance with the operating procedures.
7. Thermal conductivity meter: Thermal conductivity meter is designed and manufactured according to the good thermal conductivity of diamond. Most gems have no or very low thermal conductivity, so the general thermal conductivity meter is designed to distinguish diamonds from artificial imitation diamond products, and it is a special instrument to distinguish diamonds from other imitation diamond products. The diamond thermal conductivity meter consists of a metal probe and a control box. When the tip of the probe touches the diamond surface, the temperature drops obviously, and the measurement results are displayed by the chirp sound on the signal lamp or the instrument head. The thermal conductivity meter is more than ten centimeters long and easy to carry and use.
8. Polarizer: It is a simple optical instrument. Its principle is that plane polarized light intersects vertically and light cannot pass through. The polarizer consists of two polarizers with vertical vibration directions, a bracket and a bottom lamp. Used to detect the brightness (isotropic or anisotropic) and multicolor of gemstones. Turn on the polarizer of the lighting lamp and observe the light and shade changes of the gem sample. (1) If the sample is bright, it may be aphanitic or microcrystalline aggregate, such as chalcedony and jadeite. (2) If the sample is completely black and there is no change in light and shade, continue to observe from another angle; If there is still no change in light and shade, the sample belongs to isotropic body. Gems belonging to isotropic bodies are equiaxed and amorphous. (3) If the gem is rotated by 360, the brightness of the gem sample changes four times, indicating that the sample is not isotropic. Gems belonging to anisotropic bodies include tetragonal, hexagonal, triangular, rhombic, monoclinic and triclinic crystals. (4) If the sample rotates under orthogonal polarization, dark serpentine, grid or irregular shape can be seen, which may be the abnormal interference color of isotropic gemstones, so we should attach great importance to it at this time. Using polarizer, we can also detect the multicolor color of gemstones and verify the heterogeneity and homogeneity of gemstones.
In addition, commonly used gem identification instruments include absorption spectrometer, fluorescent lamp, X-ray diffractometer, electron probe and so on.
Treasures-diamonds, rubies, sapphires, emeralds, aquamarine, cat's eye gems, discolored gems, topaz gems, opals, tourmalines, pointed gems, garnet gems, zircon gems, olive emeralds, emeralds, quartz cat's eyes, feldspar gems, etc.
transparent
The English name of crystal is Rockcrystal, also known as spar and crystal stone.
Crystal is a colorless and transparent timely crystal mineral. Its main chemical composition is silicon dioxide, which is a substance that "comes out of the uterus" with ordinary sand. When the silicon dioxide crystal is perfect, it is a crystal; Silica becomes agate after gelatinization and dehydration; Water-containing silica gel becomes opal after solidification; When the particle size of silica is less than several microns, chalcedony, flint and secondary quartzite are formed.
The crystal with perfect crystallization belongs to hexagonal system, often in hexagonal prism shape. The cylinder is pointed at one end or at both ends, and many long cylinders are connected together, commonly known as the crystal family, which is beautiful and spectacular. The crystal of silicon dioxide is incomplete, and its shape can be described as varied. Go to Hainan Crystal Exhibition Hall, and you will be an eye-opener: in addition to the common long columns, there are sword-shaped, plate-shaped, short columns and double cones. Some are as small as fingers, and some are as big as boulders; Some are less than half a second, and some weigh more than 300 kilograms.
1824, an Austrian mineralogist named Frish Moss extracted 10 varieties from many minerals, and determined their relative hardness through scientific experiments, from which the crystal hardness was Mohs 7. Although the American National Bureau of Standards later used and popularized the more scientific Knoop hardness tester, jewelers in many countries in the world are still used to using Mohs hardness tester.
Well-crystallized crystals usually have a good herringbone fracture with parallel ridges; In amethyst and heat-treated topaz, most of them are uneven sheet fractures.
Crystal specific gravity: 2.56-2.66g/cm3.
This means that the weight of a certain volume of crystals is 2.56-2.66 times that of the same volume of water. Bulk crystals may have a slightly higher density.
Crystal stripes: colorless.
Stripes, commonly known as colors, are the result of human eyes' perception of light with a certain wavelength.
The transparency of a crystal is related to the quality and quantity of light passing through it. The transparency standard is that when light passes through crystal fragments or slices with a thickness greater than 1 cm, the reflected image can be clearly seen. If the bottom image is not clear enough and only the outline is seen, it will be translucent.
Crystal luster: glass luster. This is true for both polished and fractured surfaces.
Gloss refers to the optical characteristics of reflected light on the surface of a gem. Crystal does not reflect beautiful starlight stripes like starlight sapphire and starlight sapphire, nor does it shine with light blue waves like moonstone, nor does it shine with colors like opal.
To observe the luster of the crystal, you can hold it in your hand and look at the surface reflection with the light of a lamp or a window. The brightness of transparent crystal is related to its luster.
Refractive index of crystal: 1.544- 1.553, which is almost within this range.
Refractive index is the ratio of sine of incident angle to sine of refraction angle when light penetrates into gem crystal from air and produces refraction phenomenon.
Crystal refractive index: 0.009 (maximum), very stable.
Optical characteristics of crystal: uniaxial crystal positive light.
Crystal dispersion: 0.0 13.
Dispersion means that the refractive index of a gem changes with the change of illumination light. For example, the refraction of red light by diamonds is 2.405; 2.427 is the green light; Purple light is 2.449.
The melting point of the crystal is 17 13 degrees Celsius. In the experiment, it was found that it was brittle when heated. The crystal is baked in the flame of a flame burner. Unless it is well protected and cooled slowly, the crystal is easily broken. This kind of temperament has been thoroughly understood by the ancients. ? Introduction to Natural History reminds us: "Anyone who uses crystal objects should not pour hot soup into it, that is, the powder will crack like a broken one."
Another temperament of crystal is that it is afraid of alkali and acid (except hydrofluoric acid), which is determined by the characteristics of silicon oxide.
Gems such as agate often give off a special smell when they are heated, rubbed, blown or hit, which reminds people of garlic, horse meat, radish, pine and so on. However, the crystal has no peculiar smell in the above case.
Attached:
Chemical composition and properties of crystals;
The chemical formula is silicon dioxide. Pure colorless and transparent crystal is a variety of seasonable. The chemical composition contains 46.7% silicon and 53.3% oxygen. Because it contains different mixtures or mechanical mixtures, it has many colors. Purple and green are caused by iron (Fe2+) ions, purple can also be caused by titanium (Ti4+), and other colors are caused by color centers. The crystals contain sandy and fragmented goethite, hematite, rutile, magnetite, garnet and chlorite. Hair crystals are formed by inclusions containing hairy needle-like minerals visible to the naked eye. Containing manganese and iron is called amethyst; Iron (golden or lemon) is called topaz; Rose color containing manganese and titanium is called rose season; Smoke color is called smoke crystal; Brown is called tea crystal; Black and transparent are called ink crystals; The light green one is called stone pulp.
Crystal structure and morphology:
It belongs to the tripartite crystal system. The crystal is prismatic, with a hexagonal cone, the cylinder has horizontal stripes, and amethyst often has angular stripes. In nature, crystals are often produced in groups with beautiful shapes. .
Physical properties of crystals:
Crystal is colorless, purple, yellow, green and smoky. Glass luster. Transparent to translucent. Hardness 7. Sexually fragile. The specific gravity is 2.65. No cleavage. Shell fractures also have good herringbone fractures with equal ridges. Amethyst has obvious dichroism, while topaz and tea crystal have weak dichroism. Light emitting crystals have strong phosphorescence. Green gold placer crystal emits gray-green fluorescence under long-wave and short-wave ultraviolet irradiation. It has cat's eye, rainbow and placer gold effects. The crystal is piezoelectric.
crystal
Basically, the most important component of crystal is "silicon dioxide", which is also the most important mineral, occupying more than 65% of the crust components. It also contains various trace metals, so it will cause crystals of different colors; Moreover, crystals are widely associated with various minerals in nature, such as mica, feldspar, calcite, tourmaline, rutile, granite and so on.
The growth environment of crystals is mostly underground and caves, which requires rich underground water sources, and groundwater mostly contains saturated silicon dioxide. At the same time, the pressure inside it needs to be about two to three times that of atmospheric pressure, and the temperature needs to be between 550 and 600℃. If given a proper time, the crystal will crystallize into hexagonal columnar crystals according to the natural law of hexagonal crystal system.
Usually, in the ideal environment controlled by human beings, that is, when the physical and chemical conditions meet the above conditions, the growth rate of crystals is about 0.8 mm per day. This is also the standard production speed of many intraocular lenses in laboratories and factories. The crystal thus cultivated is the so-called "synthetic Shi Ying", which is usually cut into chips and used in electronics, computer and communication industries. Some people call it "breeding Shi Ying". Although they use different words, they actually mean the same thing. Generally, the thickness of industrial intraocular lens is about 3 cm, that is, 30mm, and it takes about 40 days to grow. It generally takes about180 days for jewelry industry to grind a crystal ball with a size above 10 cm (100mm). However, this speed is only possible in the most ideal environment controlled by human beings. In nature, the situation is not so optimistic because of raw materials, water quality, temperature, pressure and other conditions. Are constantly changing, it is difficult to achieve the ideal situation. It usually takes tens of thousands or millions of times to achieve the same growth. This is the reason why the "geological age" movement takes "million years" as the calculation base, and it is also the precious place of "crystal rock".
When a normal crystal is growing, people often find that the growth line is parallel to the cylindrical tip line. Because of the small growth space in underground and caves, especially in the event of earthquakes or crustal changes, they are even easily squeezed by other minerals, and different "crystal planes" often appear. Also, when crystals are still in liquid state, they are often wrapped by other minerals and marls and grow together, such as rutile (which will become crystals later), volcanic marls (which will become phantom crystals later) and so on. These are "part of nature", please don't treat them as "flaws".
Supplement (ghost painting symbol 2006-08-27)
Crystal is a spiritual mineral, which can bring us good luck and help us get rid of bad luck. In nature, it is regarded as the magic weapon of the elves in the stone. With its special molecular structure and continuous acceptance of the essence of heaven, earth, sun and moon for thousands of years, it has super gas field energy and incredible magical power, and can protect itself like gold and steel. It is used for practice, health preservation, gas refining, town residence, gathering wealth, praying for blessings, seeking wealth, removing obstacles, offering Buddha, making wishes, practicing, increasing wisdom, helping others and avoiding villains. The craze for crystals in the West has flocked to the East. After so many years, its love remains unchanged. The main reason is that crystal experts have been providing literature and many examples of crystal lovers for many years to prove that they contain crystals.
Because crystal has super gas field energy and memory ability, any religion in the world uses its energy and gas field to ward off evil spirits and change geomantic omen to drive away bad luck and bring good luck. Wearing crystal can keep you lucky and protect your health. The purity and magical power of crystal is an indescribable supernatural legend in Buddhism. Therefore, it is a convenient way to know the connection between crystals and get lucky.
Type and function:
White Crystal (King Crystal)
Main functions: town house, ward off evil spirits, get rid of illness, serve Buddha's spirit and be blessed with everything.
It can make the mind calm, harmonious and pure, and has the functions of concentrating, improving attention, developing thinking and developing potential ability. People who are terminally ill and full of twists and turns are mostly sick because of too much negative energy in the human body or the possession of qi, which leads to weakened vitality, poor spirit and unsatisfactory work. The magnetic field of white crystal can break through the bad airflow, purify the whole body and restore human health. When the negative energy dissipates, it is the beginning of good luck.
Topaz (Lucky Crystal)
Main functions: turn money into treasure, create unexpected wealth and strengthen the digestive function of the stomach.
There are two kinds of cosmic light related to wealth, one is green light and the other is yellow light. The yellow light in topaz brings partial fortune, which can create unexpected wealth, that is, "partial fortune". Topaz can strengthen the second round of the human body, that is, the umbilical wheel. Besides stomach, liver, kidney, spleen and pancreas can also be regulated.
Green Ghost Crystal (Professional Crystal)
Main functions: create career wealth, advocate wealth, recruit wealth and collect wealth. ?
The green light in green tea crystal is the light of modern economic artery. If you want to expand your business and attract more wealth, you need green crystal. The green light in the green ghost crystal has the power of highly condensing wealth. Green crystal can enhance the immune system function and make people naturally peaceful and rich.
Amethyst (spiritual crystal)
Main functions: develop wisdom, improve intuition, be popular, calm, and promote interpersonal relationships.
Similar to the frequency of brain waves, it has the effect of calming the nerves and relieving bad temper. It can cure insomnia, develop wisdom, strengthen memory and enhance interpersonal relationships. Purple is the feminine essence, which dominates the right brain world, that is, intuition and subconscious. People who often use their brains are especially suitable for more amethyst, which can help people to concentrate when thinking and improve the vitality of their brains. It can make people think calmly in a difficult situation. Amethyst is a kind of restrained divine power, which can calm people's emotions and play a magical role in love, friendship, affection and the relationship between superiors and subordinates.
Amethyst Cave (Feng Shui Crystal)
Main functions: Town house, improving the geomantic omen in the house, and gathering wealth.
Amethyst Cave, also known as Fengshui Stone, has dense crystal columns, and mutual energy vibration can condense the indoor magnetic field, which is auspicious and safe. Amethyst Cave itself has a strong magnetic field. It has the function of filtering, which can demagnetize smaller crystals. Its gas field is endless, providing us with the energy we need every day. At the same time, it can adjust the indoor temperature, keep dry and deodorize, also known as dehumidifier. The amethyst cave is placed at the door, which can ward off evil spirits, get in the way and absorb the essence of the sun and the moon. Amethyst Cave is an indispensable treasure in our life.
Backbone crystal (crocodile crystal, healing crystal, mind crystal)
Main functions: meditation, practice and scholarship? The magnetic field is brave and superior, strengthening the function of the lower body (submarine wheel).
Unique shape, powerful function, super purification ability, can treat energy and absorb sick gas. It is the hope of seriously ill patients and an indispensable weapon for gas practitioners. The magnetic field is strong, and the energy emission mode is different from that of white crystal, which radiates downward. Therefore, it can be used in balance with the white crystal (for example, the white crystal is placed at the head of the bed and the backbone crystal is placed at the end of the bed). The trunk contains four elements: earth, water, fire and wind.
Hair crystal (authoritative crystal)
Main functions: enhance courage and decision-making ability.
As long as the crystal contains needle-like and filamentous organisms, it is hair crystal, and its hair drives the magnetic field to double its energy, such as white hair crystal, tea hair crystal, purple hair crystal and yellow hair crystal. At the same time, hair crystal can give indecisive people more courage, and it is an indispensable crystal for those who want to take responsibility and expect to do great things.
Powder crystal (hibiscus crystal, love crystal)
Main functions: promoting marriage and enhancing feelings.
Pink light can improve interpersonal relationships and gain popularity. Like amethyst, it can lubricate the feelings between men and women and bring a beautiful marriage. At the same time, developing heart chakras can help people pursue love, enhance contact, control cardiopulmonary function, and contribute to the health of circulatory system and respiratory organs.
Tea crystal (smoke crystal, ink crystal)
Main function: strengthen the submarine wheel of human body and help people rejuvenate.
The magnetic field of this crystal can be used to strengthen male sexual dysfunction or female diseases, as well as people with weak reproductive organs. Enhance human immune function, activate human cells, slow down aging and restore youthful vitality. Improve reaction ability and strengthen analysis and judgment.
Simple ways to clean the crystal:
1. Soak the crystal in salt water (sea salt and coarse salt) for 24 hours, then wash it with clear water and dry it with clean cotton cloth (except amethyst cave).
2. Soak the crystal in seawater.
3. Putting the smaller one in the amethyst hole can also achieve the function of purification and degaussing.
Crystal is the purest magnetic field among all natural minerals, which is of great help to our daily life and health. However, if you blindly rely on the crystal and don't work hard, its effect is still limited. Crystal is a kind of gem with great energy. Any light or energy emitted through the crystal will become infinite. If you know how to use crystals, crystals will be of great help to our bodies, our houses (geomantic omen) and our luck. Therefore, the crystal is to help you achieve your goal, not to let you enjoy it.
So gems are different from crystals. Gemstones are not made of crystals.