What are precious stones?

Precious stones can be collectively referred to as gemstones, referring generally to all kinds of materials that have been faceted, carved, or kept in their original form to become jewelry or handicrafts. However, in a narrower sense, it refers only to natural gemstones.

I, the classification and basic characteristics of the gemstone broadly speaking, the gemstone is the natural and artificial jewelry and jade collectively, referred to as gemstones. It covers all natural and artificial jewelry and jade, that is, including all minerals, rocks and organic materials that meet the requirements of the process.

1. ClassificationIn order to standardize the classification of domestic gems and stones, China has formulated a unified classification scheme for gems and stones. China's national gemstone classification system takes full account of the international universality and customary, and tries its best to adopt the principles of classification that are now commonly used internationally and becoming more and more uniform. At the same time, in order to highlight the characteristics of China's traditional classification of precious stones and jades, and to adopt a combination of international and domestic methods, jade is specially divided out separately.

(1) natural treasure and jade stone natural jewelry and jade stone mainly refers to natural gemstones, natural jade, natural organic gemstones, etc., which are the main treasure and jade stone ornaments in the market. In the circulation of precious stones and jade, if there is no special instructions, the usually said precious stones generally refers to natural precious stones and jade.

Natural gemstones are mineral single crystals (which may contain bicrystals) that are produced by nature and have the characteristics of beauty, durability, rarity, etc. and a certain craftsmanship value, which can be processed into jewelry. Generally bright colors, high transparency, hardness, chemical stability. Such as diamonds, rubies and so on.

Natural jade refers to the output from nature, with beauty, durability, rarity and other characteristics, can be processed into ornaments of mineral aggregates, a few amorphous. Such as jadeite, nephrite, etc.

Natural organic gemstones refers to biologically generated by nature, partially or wholly composed of organic substances, can be used to process into jewelry and decorative materials. Such as amber, coral, pearl, coal essence, ivory and so on.

(2) Artificial gemstonesArtificial gemstones refer to materials that are completely or partially produced or manufactured by human beings and used as jewelry and decorations, mainly including synthetic gemstones, man-made gemstones, assembled gemstones, and reconstructed gemstones. Synthetic gemstones refer to the crystalline or amorphous bodies that are completely or partially manufactured by artificial means and have known counterparts in nature, whose physical properties, chemical composition and crystal structure are basically the same as those of the natural gemstones of the counterparts. Such as synthetic diamonds, synthetic sapphires, etc.

Artificial gemstones are crystalline or amorphous bodies that are manufactured artificially and have no known counterpart in nature. Such as artificial yttrium aluminum garnet, artificial strontium titanate, etc.

Aggregate gemstones are gemstones that are artificially assembled from two or more pieces of material and that give the impression of a whole. For example, a collodion sapphire is made by combining a natural sapphire and a synthetic sapphire.

Reclaimed gemstone refers to the fusion or compression of pieces or shavings of natural gemstones by artificial means, with the appearance of the whole of the jewelry and jade. For example, by amber chips pressure knot

Knowledge Links China's national gemstone classification system National Jewelry and Jade Quality Supervision Center of gemstones into two categories, namely, natural jewelry and jade and artificial gemstones.

Natural jewelry and jade include: natural gemstones (such as diamonds, rubies, sapphires, emeralds, opals, aquamarines, etc.), natural jade (such as jadeite, nephrite, ciuyu, dosan jade, quartz jade, etc.) and natural organic gemstones (such as pearls, coral, amber, coal essence, etc.) three categories.

Artificial gemstones are divided into four categories: synthetic gemstones (such as synthetic diamonds, synthetic rubies, synthetic emeralds, etc.), man-made gemstones (such as man-made yttrium aluminum garnet, man-made strontium titanate, etc.), collocation of gemstones (such as collocation of opal, collocation of sapphire, etc.) and recycled gemstones (such as recycled amber, recycled turquoise, etc.).

Additionally, there is a special category of imitation precious stones (such as imitation pearls, imitation crystals, imitation emerald, etc.), but it is not the real sense of precious stones.

Into, with the complete amber illusion of the reconstruction of amber.

(3) imitation gemstone there is such a class of gemstone, this kind of gemstone is only used to imitate the similar natural gemstone color, appearance and special optical effects of artificial gemstone, and for imitation of another kind of natural gemstone natural jewelry jade. Such as the use of colorless natural zircon to imitate natural diamonds.

2. The value factor gemstone is expensive, high-grade high-quality gemstone is worth a lot of money. During the Spring and Autumn and Warring States Periods, the King of Qin was willing to exchange 15 cities for Zhao's collection of "He Shi Bi". The value of precious stones can be seen amazing, and even due to a precious stone can trigger a war.

Knowledge LinksThe determinants of the value of precious stones are, first of all, attributable to the creation of nature, especially naturally occurring mineral rocks.

The second is beautiful. If a precious stone is not beautiful, it cannot be called a precious stone. The more beautiful, the more expensive.

Third, it is durable. For gemstones, generally the more durable the gemstone, the more expensive it is.

Fourth, it is rare. Rarity plays a very important role in determining the value of gemstones. As gemstones, the fewer the production, the greater the demand, the higher the value.

Fifth, is the demand. Demand is also one of the factors that determines whether a precious stone is expensive or not, if the demand is too high, it will lead to a rush and a rush fever, making its price rise.

Sixth, is easy to carry.

3. The basic characteristics of precious stones as precious jewelry should generally have the characteristics of beauty, durability, and rarity. In addition, it must be small and exquisite, easy to carry, and to fashion, can be more convenient to save and transfer, can play a role in preserving and increasing value.

(1) beautiful crystal bright, brilliant, magnificent and beautiful is the first condition that reflects the value of gems and stones. Gemstones are generally or colorful, or crystal clear, or with a unique optical effect; jade is mainly manifested as a delicate texture, polished with a warm, bright aesthetic.

Gemstones can be divided into two categories, colored gemstones and colorless gemstones, according to their colors. Among them, colored gemstones generally require bright, soft, pure and uniform color. Such as rubies, sapphires and emeralds have pure and brilliant red, blue and green; colorless diamonds can show different spectral colors if they are processed through cutting and grinding, which is called "fire color", commonly known as "fire"; opal itself has a variety of colors of the Colorful color spots, giving people a beautiful visual impact. Although colorless gemstones do not have bright colors, they generally have a strong luster and high transparency. Some colorless gemstones can be processed to produce special optical effects such as cat's eye, starburst, color change and color tourmaline. "A stone is not a treasure until it is polished". The beauty of most gemstones is latent and can only be fully revealed after proper processing.

(2) DurabilityMany precious stones are used for jewelry, and people can't avoid friction and collision with other objects when wearing them. Therefore, most of the precious stones need to have a certain degree of hardness, toughness and chemical stability, in order to make jewelry on the precious stones do not lose their luster due to wear and tear.

(3) rare "rare and precious, less expensive", which is known to the world, the rarity of gems and stones include both the variety of rare, including the quality of rare. Diamonds are expensive, one of the reasons is because it is very rare. Fine, flawless emeralds are even rarer, so a high-quality emerald may cost more than a diamond of comparable size and quality.

Also, changes in the production of precious stones determine the price. When natural amethyst was found only in Europe, it was considered a rare and precious gemstone and was expensive, but when large-scale amethyst deposits were developed in Brazil, its price plummeted. Synthetic gemstones are identical in nature to natural gemstones, but generally differ greatly in price from natural gemstones.

Tips Important properties of gemstones 1. Color Different gemstones generally have different colors, even if the same color, in terms of characteristics, shape can not be exactly the same, there are often different shades, intensity.

2. Hardness The durability of precious stones depends largely on its hardness. Hardness refers to the degree of abrasion resistance of precious stones, or the reflection of other substances on it after scratching, grinding, rubbing.

3. Transparency Transparency refers to the ability of the gemstone to transmit light. Generally two millimeters thick precious stones prevail, light can be completely through when called "transparent", part of the through when called "translucent", basically can not pass through or completely can not pass through is known as "opaque ". Generally speaking, the same kind of precious stones, the higher the transparency, the more precious.

4. Lustre is a surface phenomenon that reflects light directly to the human eye. Brightness is a form of expression of the beauty of precious stones, the brightness of transparent precious stones is related to the strength of its luster, luster is a very important criterion for judging the brightness of precious stones.

5. Density density is the main physical properties of precious stones, different precious stones have different fixed density, according to different density can distinguish between different types of precious stones.

6. fluorescence and phosphorescence of many gemstone with some special light source irradiation or after heating, will emit a variety of colorful visible light. When the above external conditions disappear, the gemstone luminescence phenomenon also disappears, this light is called fluorescence. After the disappearance of external conditions, the gemstone can still glow in a longer period of time, this light is phosphorescence.

7. Inclusions in the growth process of precious stones, the outside world or small crystals (solid, liquid, gas or mixtures) often mixed into the accumulated material, in an irregular form, that is, for the inclusions. In nature, the general gemstone contains a certain number of inclusions.

8. dispersion of white light into spectral colors called dispersion. The ability of various gemstones to break down light into various colors is different, and thus the dispersion is also different.

9.disintegration and fracture disintegration, also known as "cleavage", for the crystal or grain in the external force under the blow, along a certain direction of crystallization into the plane of the inherent nature of the fracture; fracture is the minerals in a certain external impact, not in accordance with the direction of the crystallization of the rupture, but the formation of a disconnected surface. Different gemstones, their resolution and fracture are not the same.

10. Birefringence and polychromaticity birefringence is a beam of light incident on the anisotropic crystals, decomposed into two beams of light and refracted in different directions of the phenomenon. Mainly divided into hexagonal, tetragonal, monoclinic, triclinic and rhombohedral crystal system, and amorphous and isotropic crystal system of minerals are monorefractive; mineral polychromy refers to the nature of the color change based on the incident light source and the angle of incidence of different.

Two, the naming principle of gemstone for a long time, the international jewelry industry on the naming of gemstone does not have a unified principle and standard, a variety of methods, even if the same kind of gemstone name is not the same.

Traditionally, the naming methods of precious stones are mostly used: direct naming by color, such as ruby, sapphire, aquamarine, amethyst, etc.; naming by special optical effects, such as cat's eye, aventurine, etc.; naming by origin, such as serpentine jade origin named Xiuyan Jade, named by the famous origin of nephrite jade, Hetian Jade, etc.; direct naming by the name of the minerals and rocks

Knowledge Links China National standard rules for the naming of gems and stones natural gemstones Directly adopt the basic name of natural gemstones or their mineral names, without the addition of the word "natural", the origin is not involved in the naming, the use of two or more natural gemstones name combination of the name is prohibited, and prohibit the use of ambiguous commercial names.

Jade The basic name of natural jade or its mineral or rock name is used directly, and the word "jade" may be added after the name of the natural mineral or rock, except for natural glass. In particular, it is not permitted to use "jade" or "jade stone" alone instead of the specific name of natural jade.

Organic gemstones The basic name of a natural organic gemstone is used directly, without modifying the name of the natural organic gemstone by its origin.

Synthetic Gemstones The word "synthetic" must be added before the name of the natural gemstone to which it corresponds, and it is prohibited to use the name of the production plant or manufacturer to directly define the name.

Synthetic gemstones require the word "synthetic" in front of the name of the material, and it is prohibited to use the name of the factory, manufacturer or production method.

Pieces of gemstones need to be written layer by layer the name of the constituent materials, and in the name of the constituent materials, followed by the word "pieced stone"; or the name of the top layer of the material with the word "pieced stone".

Reclaimed stones must be preceded by the word "reclaimed" for natural stones.

Imitation Gemstones must be preceded by the word "imitation".

Name (this is a method commonly used in the international jewelry industry, scientific and accurate), such as spinel, beryl, peridot, etc.; the use of some traditional names handed down from antiquity, such as jade, amber, etc., which are often related to some ancient legends; to manufacturers, production methods, style process names and commercial names, such as Chatham emeralds, flux method, rubies, etc., but China prohibits the use of the word "imitation" in front of the imitation gemstone. Ruby, etc., but China prohibits the use of such naming methods.

International so many naming methods, resulting in the inaccuracy and ambiguity of the name of the precious stones, the formation of some of the names of the precious stones confusing situation. In order to better regulate the domestic gem and jade stone circulation market, China National Jewelry and Jade Stone Quality Supervision and Inspection Center drafted the national "Jewelry and Jade Stone Names" (GB/T16552-2003), which stipulates the naming rules of jewelry and jade stones, taking into account the commercial and traditional naming habits, and with reference to the international common names and rules.