Natural crystals
Natural crystals are formed under natural conditions, growing deep in the earth’s crust and usually undergoing violent crustal movements such as volcanoes and earthquakes. Natural crystal belongs to mineral resources, which are very rare and precious, and belong to one of the gemstones.Wide variety
Synthetic crystals
Synthetic crystal is also known as regenerated crystal is a single crystal, also known as synthetic crystal, piezoelectric crystal. Recycled crystal is made by using the hydrothermal crystallization method to “imitate the growth process of natural crystal”, by placing natural silicon ore and some chemicals in an autoclave and gradually cultivating it over a period of 1-3 months (for different crystals). It is exactly the same as natural crystal in terms of chemical composition, molecular structure, optical properties, mechanical and electrical properties, while recycled crystal is purer and better color than natural crystal in terms of birefringence and polarization. After processing (cutting, grinding, throwing), the particles of various shapes are crystal clear, dazzling, and wear-resistant and corrosion-resistant.
Molten crystal
There are many people on the market who call smelted crystal also called synthetic crystal, which is inaccurate, generally smelted from crystal waste at high temperature and high pressure, rather than crystallized, and does not have the crystal characteristics of crystal, so it cannot be confused with smelted crystal; However, the smelting crystal is resistant to high temperatures, and the smelted crystal made of high-quality silica can be made into practical products such as crystal cups, baking trays, tea sets, etc., in fact, the crystal coffin of Chairman Mao Zedong, a great man, is made of high-quality crystal smelted in the East China Sea.
K9 glass crystal
Some people also call K9 glass synthetic crystal, which is even more wrong, although K9 glass is smelted with silica as the main raw material, but 3~4% lead is added in the smelting process, which is actually crystal glass; Why add lead, generally the glass is blue or green, it doesn’t look like crystal, but after adding lead, the whiteness of the glass is very high, and it looks very much like crystal, especially the K9 glass containing 3~4% is the most like crystal, so it is more appropriate to call K9 glass imitation crystal.
Identification
Touch the crystal with your hands, natural crystal is usually much cooler than artificial crystal; Visually, natural crystals usually have cotton wool-like inclusions, which are not found in artificial crystals.
For monochromatic crystals such as amethyst citrine, it is usually necessary to observe its dichroism, even the top amethyst citrine is also chromatic, and this method can be used to identify whether or not to add color.
Natural crystals generally have flocculent (cotton locks), which is commonly known as flaws, which are small holes in liquid water and carbon dioxide, while synthetic crystals will not have such characteristics.
Crystal is divided into color grades, and there are many factors that affect the price of crystal, unlike diamonds, which can be judged by 4C, so everyone has to listen and see more to really distinguish them. The general criterion is that the larger the crystal, the more transparent the better, the more delicate the color the better, and the more typical the shape the better. However, the most important thing is to like it, and there are roughly the following ways to identify the authenticity when purchasing:
(1) Look: natural crystal in the formation process, often affected by the environment always contains some impurities, when observing the sun, you can see a faint uniform fine horizontal stripes or catkins like substances, commonly known as (ice cracking, cotton wool). The fake crystal is mostly smelted with residual crystal slag and glass slag, polished and colored, and there are no uniform stripes and catkins.
(2) Check with dichroism: natural amethyst has dichroism, and false crystal has no dichroism.
(3) Check with a magnifying glass: Check under the transmitted light with a ten-fold magnifying glass, and the bubbles that can be found can basically be determined as false crystals.
(4) Of course, the most authoritative way is to send it to a professional organization for identification.
Distinguish from similar gemstones
Although the birefringence index of amethyst is similar to that of iolite (0.008 to 0.012), the difference in color and pleochroism is more pronounced. The color of lapis is purple-blue-blue, and the purple of amethyst rarely appears. Laplite has obvious polychromatic properties, visible to the naked eye, and different colors can be seen when viewed from different directions. Amethyst, on the other hand, varies in different shades of the same color (blue-violet to purple in different shades). In addition, amethyst is a uniaxial crystal with a bull’s-eye interference pattern, while iolite is a biaxial crystal.
Crystal feldspar
Colorless crystals are difficult to distinguish from colorless feldspar because of their close refractive index and density. The main method is magnification. Feldspar has two groups of extremely complete cleavage, and microscopically it can be seen that the two groups of cleavage intersect to form “clam-like” inclusions or fine straight textures, while crystal has no cleavage development, and only intermittent irregular cleavage can be seen from time to time.
The difference between natural crystals and artificial crystals
Crystals are divided into natural crystals and artificial crystals. China has abundant natural crystal resources, but the rise of crystal fever in China started from artificial crystal. The value of natural crystal mainly lies in the functional effect of its mineral magnetic field on the human body
(1) The color distribution of natural purple crystal is uneven, irregular flake distribution, and there are gas-liquid inclusions; Synthetic purple crystals are uniform in color and have a daughter crystal nucleus in the center.
(2) Natural crystal also has colors such as citrine and smoky quartz, if it is blue and orange, it is artificially changed. The difference between color change crystals and natural crystals is that the color of color change crystals is bright and uniform, and there are no irregular flake color clusters in them. Artificially altered crystal prints will slowly fade after a long period of use, losing their decorative and appreciative value.
(3) Observing the sun, no matter how advanced the natural crystal jewelry, you can see the faint uniform fine horizontal lines or catkins texture, while the fake crystal jewelry is generally regenerated by smelting and regenerating with residual crystal slag or glass, and imitated by polishing and coloring, and the uniform stripes and catkins can not be seen in the sun.
(4) In the sun, natural crystal jewelry can radiate a beautiful brilliance no matter which angle it looks at, while fake water jewelry does not have this brilliance.
(5) The refractive index of natural crystal is 1.54, and the refractive index of false crystal is generally less than 1, (there is no error here, there is no refractive index less than 1.) The refractive index is the ratio of the speed of light propagation in a vacuum to the propagation in a medium, which must be greater than 1). Moreover, the refractive index of glass is between 1.5 and 1.9, which cannot be inferred from the truth or falsity or is far from the refractive index of natural crystal. Crystal is an excellent quartz crystal, most of which are colorless and transparent, and a small amount of different trace elements show different colors. It is transparent, high hardness, good refraction, necklaces and glasses made of high-quality natural crystal processing, and has become a high-end decoration and practical product for beautifying life and dispelling diseases and health care.
Natural Synthesis
Fashionable collectors like to collect natural crystals, but they are often blinded by the large number of synthetic crystals in the market. Crystals on the market:
Smelted crystal (synthetic crystal): mostly made of quartz powder, glass slag, crystal scraps, etc. The hardness of smelted crystal is generally between 5.5-6, so its hardness is lower than that of crystal. (Crystal is 7)
Cultured crystals: Cultured crystals refer to the use of natural crystals as seeds, and then give natural crystals high-pressure conditions for growth, and there are silica-rich molecules in the breeder. Then the silica molecule grows around the natural crystal species, and the crystal composition (molecular formula) is the same as the natural crystal, the only difference is that the magnetic field of such a crystal is not as strong as that of natural crystal.
The so-called Austrian crystal is actually often leaded glass, generally add lead elements to the glass, the refractive index of the glass will be very high, the dispersion will also be enhanced, but the hardness will be reduced, the higher the lead content, the lower the hardness.
Artificial crystal is divided into smelted crystal and cultured crystal: with the increase in the value of crystal, the number of people who like it, crystal has also aroused the interest of counterfeiters, and the common counterfeiting methods in the crystal market at this stage are:
Pictographic crystal: Some of the scenery inside the crystal is lifelike, don’t patronize the pictographic scenery inside the crystal, many people have been able to use the AB glue superbly, cut the crystal, add a landscape in the middle (small trees, small animal shapes), and then glue it up. I took it to my hand and saw that it was very beautiful, and I bought it, and I thought it had investment and collection value, but unfortunately this thing was man-made.
Titanium crystal tree: Titanium crystal is the most expensive crystal in the crystal, and counterfeiters will certainly not let go of such a good product. In the natural environment, it is completely possible to grow a tree-like titanium crystal in the crystal, but there are very few such goods, so how do our counterfeiting experts do it, make a hole under the white crystal, and the laser dots the plate-shaped titanium crystal into it, so the value of this crystal can soar dozens of times. Often, some titanium crystal ring surfaces are made by cutting the titanium crystal parts into plates and bonding them with the crystal of the round surface.
Crystal products
Look at the raw materials: well-selected crystal products, you should not see the glue mouth and cotton wool; The texture is pure, smooth and crystal clear.
Look at the workmanship: The processing process of crystal products is divided into two types, namely grinding and carving. For example, crystal necklaces, bracelets, earrings, etc. are abrasives; Statues of Goddess of Mercy and snuff bottles are carved objects.
Look at polishing: The quality of polishing directly affects the value of crystal products. Polishing is divided into soft polishing and hard polishing.
Look at the eyelets: For crystal products (such as necklaces, bracelets, and Buddhist beads), it is necessary to see whether the eyelets are straight, whether the thickness of the holes is uniform, and whether there are small cracks. The hole wall must be clear and transparent, with no “white marks”.
Look at the color: Even in the same type of crystal, the texture and color of different parts of it are also different. It belongs to monochrome, and the chromaticity should be uniform; If there is a shade on the same crystal, it is required that its tone and texture are beautiful and generous.
Look at the culture: if the inclusions in the crystal can be related to culture, religion and history, the price is often several times or even hundreds of times higher than the value of the crystal itself.
Crystal
- Crystal Overview
- The growth environment of crystals
- Understanding Crystal Clarity
- How to identify different grades of crystals
Crystal Crafts
- Crystal Crafts Meaning
- The effect of crystal crafts
- Crystal Crafts Customer Identification Method
- Precautions for maintenance and cleaning of crystal crafts