1, marking the original stone
On the basis of correct evaluation of the original diamond, the design intention is marked on the diamond with a special pen, and the cutter polishes the diamond according to the mark. Scoring is the first step of diamond cutting and grinding, and it is also the most important work in the whole cutting and grinding process. It directly affects the economic benefits of diamond cutting and polishing, and also affects the perfection of the final diamond products. Therefore, people engaged in this work must have solid gemmological professional knowledge, rich practical experience and skilled processing technology. His ultimate goal is to make the largest, cleanest and most perfect finished diamond and create the greatest economic benefits.
Step 2 divide the original stone
For various reasons, it is necessary to divide the original stone. It is also a very important job to divide the rough stone, which directly affects the quality and ultimately the value of the finished diamond. The important factors to be considered when dividing the original stone are: the shape of the original stone, the internal defects of the diamond, twins and crystallographic characteristics. For example, the octahedral diamond usually adopts the method of topping the stone, that is, sawing the original stone into unequal parts, as shown in Figure 4-7. This will gain greater commercial value. Take a 6-carat rough stone as an example. If the rough stone is divided according to the truncated top, the weight of the bottom part is about 4 carats and the top part is about 2 carats. The finished product may show that one weighs 2 carats and the other weighs 1 carat. If the two parts of raw stone weigh 3 carats, and the yield is still calculated at 50%, two finished products of about 1.5 carats will be obtained. Obviously, the commercial value obtained by the first method will be greater.
Step 3: Rough grinding
Rough grinding is the process of shaping the rough diamond. It is a cutting or cutting grinding process, similar to machining wood or metal on a lathe.
The process of rough grinding of diamond is as follows: firstly, the diamond after waist grinding is stuck on a fixture, and the fixture is installed on the card of the rough grinding machine.
Clamp the other one on the fixture as a cutting tool. The operator holds the long handle with his arm. When the rough grinder drives the diamonds to rotate, the two diamonds contact each other and the handle is ground and shaped.
Step 4 amend
Polishing is the process of grinding rough diamonds into final products through a series of processes. The main components of polishing equipment are grinding disc, clamp and pliers mouth. Polishing is a highly technical technology, which requires diamond cutters to know a certain process and have rich experience.
Diamond jewelry processing
One of the main functions of diamonds is to wear them to decorate and beautify people's lives. In order to wear them, they must be made into jewelry. Therefore, the processing of diamond jewelry should be an extremely important part of the whole diamond processing. There are two basic methods for diamond jewelry processing:
4.3. 1 Manual handling
Handmade diamond jewelry processing is the most primitive manufacturing method and the most basic processing step. Whether casting or forging, hand-made jewelry should be used as a mold. Therefore, in the jewelry processing factory, the craft is often the most skilled. The basic process of manual processing of diamond jewelry is:
(1) Pre-preparation: After obtaining a complete jewelry design pattern, the processor should first read it to understand the design intention of the jewelry designer and analyze the overall structure of the jewelry and the setting method of the diamond. On this basis, prepare processing materials and adjust processing equipment.
(2) Piece-by-piece processing: according to the results of structural analysis and the principle of taking the greatest priority, the whole jewelry is decomposed into several independent parts, and then metal materials are prepared according to the weight, thickness, width, thickness and length of each part, and pressed, laminated, stretched, cut and plated with tools such as tablet press, wire drawing machine, nest anvil, pit iron, golden hammer and scissors. As well as tools such as files and pliers. To set diamond jewelry, we must first process the setting of the main stone and the auxiliary stone.
(3) Assembly and molding: according to the design pattern, put the processed scattered components on the cement, and pay attention to the overall coordination and high and low levels, which is very important for the perfect expression of design requirements. After the whole arrangement, the gypsum slurry prepared in advance is poured on the jewelry prototype bonded with rubber. When the plaster dries, remove the plasticine, and then the whole front of the jewelry will be firmly shaped by the plaster.
(4) Integral welding: firstly, clean up the welding spots on the jewelry surface on the gypsum base, prepare several metals for welding from high temperature to low temperature, use borax as flux, and use the welding tool of balloon-oil pot-fire blowing structure to weld in turn according to the order of first big and then small. After welding, the gypsum powder of the jewelry blank is cleaned, and the small parts are welded with low temperature metal. Pay attention to check whether the solder joint is real, try to complete the welding in a short time and keep the solder joint clean.
(5) Fine treatment: Although the jewelry after welding is basically formed, it is quite rough, so it needs to be finely polished with tools such as file, sandpaper, paper and leather grinding wheel to remove all redundant welding and file marks. If there are sand holes that cannot be filed, they need to be repaired by fire welding. When doing this process, it must be fast and accurate to avoid the original solder joint falling off.
(6) Diamond inlay: Diamond is the center of the whole diamond jewelry, so the whole process from design to processing should put diamond inlay in the first place. First of all, choose an appropriate setting method, and use tools such as crane, fine file, pliers, tweezers and wood clips to complete the diamond setting process through gem observation, gem placement, setting position and gem reinforcement. When inlaying, usually put the auxiliary stone first, then put the main stone, and then grind the melon with beads or polish the edge with rubber wheels.
(7) Polishing and cleaning: Polishing is to improve the smoothness of the metal surface. Commonly used tools are sander, brush, green wax yellow cloth wheel and red wax white cloth wheel.
(8) Post-treatment: When diamond jewelry is processed, the non-ferrous metal layer (such as electroplating 18K platinum, etc.). ) is often added to the metal part of diamond jewelry to achieve novel artistic effects. In addition, as an industrial product, the factory logo, metal purity, diamond weight and other parameters must be printed on diamond jewelry before leaving the factory, so as to complete the whole diamond jewelry production process.
Casting process
Casting is a popular method for processing precious metal diamond jewelry. The processing steps of the method are as follows:
(1) Jack-up: make a jewelry template by hand, and weld a nozzle strip at a proper position to ensure the smooth pouring of metal liquid during casting as a casting template. In some cases, the technique of relief is also used to make the prototype of jewelry directly by carving wax, which is called waxing board.
(2) Glue pressing and wax injection: the jewelry pattern is sandwiched between plastic raw films, the raw films are stuffed into pre-selected aluminum frames, and the pressed patterns are filled with film fragments, and then pressed in rubber by a hot press (150℃) for 30-60 minutes, and then the film is cut by a scalpel according to certain technical rules to make a so-called glue mold. The melted paraffin was injected into the rubber mold with a wax injection machine (70-90℃,1-1.2×105pa) connected to a vacuum pump, cooled and hardened, and then carefully taken out from the rubber mold to form a so-called wax mold.
Remove the burr on the wax pattern, modify the ring mouth according to the customer's requirements, plant it on the prepared wax rod, and plant a batch of jewelry wax patterns in one direction in turn to form a wax tree. The smaller species are placed at the top of the tree, while the larger species are placed at the bottom of the tree. The angle of species should be about 45 to ensure that liquid metal can be poured into all parts smoothly.
(3) Pouring: firstly, the wax tree is weighed and fixed in a pouring cage, gypsum powder and water are evenly mixed according to the ratio of 1: 40, put in a vacuum extractor for about 90 seconds, taken out and poured into the pouring cage, and carefully taken out after vacuumizing for about 90 seconds. Gypsum can be solidified in about 2 hours, and after 1-2 hours of wax evaporation, the casting cage can be put into the oven to bake gypsum. After about 6 hours of gradual heating, gypsum can be baked and made into gypsum molds.
In the next step, the metallic material and the bonding coating are heated in a gold melting furnace. When the alloy is completely melted and stirred evenly, the golden water is poured into the gypsum of the vacuum machine or centrifugal casting machine, and the jewelry blank is made after cooling.
(4) Embracing and frying gold: Embracing refers to the process of carefully repairing the jewelry blank; Gold speculation refers to the process of removing dirt and brightening metal jewelry after it is held in the mold. These two processes are essential for processing diamond jewelry.
(5) Stone setting and post-treatment: After gold frying, the stone setting, polishing, cleaning, typing, printing and manual production processes are the same.