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WHATISA DIAMOND?? A diamond is a transparent gem made of carbon, one of the earth's most common elements. The formation of diamonds began very early in the earth's history, when the condensation of solid matter into a sphere caused the centre of the planet to become subjected to incredible extremes of temperatures and pressure. It was these conditions that caused deposits of carbon to begin to crystallise deep in the earth. As the earth's surface cooled, volcanic activity forced streams of magna (liquid rock) to the surface, carrying with it the diamond crystals. The atomic structure of a diamond gives it the property of being the hardest substance known to man, However, many people expect a diamond to be unbreakable. This is not true. A diamond's crystal structure has "hard" and "soft" directions. A blow of sufficient force, in a very exact direction, can crack, chip, split or even shatter a diamond.
WHERE ARE THEY FOUND?? Diamonds can be found all over the earth however, concentrations of these carbon crystals can form in placer oriented locations (sand and gravel benches) If an area is prone to seasonal or flash floods, the most likely location to find diamonds are in the lighter gravels or leading compacted clay benches. Oxbow lakes are another excellent place where concentrations of diamonds can be found. These natural diamond "catch areas" are found in flood plains and river bottoms.
TOP MINING SITES.. Angola 1.Catoca diamond mine 2.Fucauma diamond mine 3.Luarica diamond mine Botswana 1.Damtshaa diamond mine 2.Jwaneng diamond mine 3.Letlhakane diamond mine South Africa 1.Baken diamond mine 2.Cullinan diamond mine
MINING SITES IN INDIA India 1.Golkonda 2.Kollur Mine 3.Panna 4.Bunder Project 5.Diamond mine
DIFFERENT WAYS OF EXTRACTING IT 1.Hard rock When it comes to diamonds, hard rock means blasting kimberlite volcanic rock. Diamond bearing kimberlite carries these stones to the surface through "pipes". The only way to free the stones is to blast and crush the ore for final separation. Within the hard rock mining classification, there are two main diamond mining methods:
A)Open Pit This type of Hardrock diamond extraction technique is simply a top down mining approach. Typically a long spiral (corkscrew) open pit shaft follows the vertical kimberlite volcanic ore vein deep into the earth. There are practical limits on depth with this type of diamond mining. Depending on the formation of the kimberlite shaft(s), a horizontal or sloping underground tunneling method will be employed. These shafts, also called a "decline" will be reinforced or supported by using a variety of bracing methods. Leaving pillars of standing rock or timber braces are some of the techniques used to hold up the rock roof as mining progresses.
B)Placer Placer diamond mining, also called alluvial mining, involves sifting through sand and gravels to extract diamonds. This method is common in Africa and used by most of the local people for diamond mining. The number one reason placer mining is so common in Africa is that that Continent hasn't had glacial scouring of the diamond deposits. Kimberlite has decomposed and diamonds have been carried by rivers and streams into concentrations, both gravel (alluvial) and into clay, particularly blue clay, settlements.
CRUSHING AND MILLING The material is extracted from the mine. The processing phase is lengthy and begins with crushing and/or milling the material. The first step is to separate the diamonds from all other material. This is done on a large scale because diamonds occur in extremely small quantities when compared to overall volume of earth that must be moved to find them. The conglomerate is put into a large crushing machine and smashed until the crystals are released. This must be done carefully so as to not harm the precious gems (Bruton, 1978). Milling the material is more suitable for some deposits. Milling is a process where the diamondiferous material is placed in huge rotating drums that contain water. The material slowly disintegrates leaving only raw diamonds. Milling is more efficient at collecting smaller fine diamond crystals
FINISHING TOUCHES Once extracted, the diamond must be polished then can undergo a multitude of cuts. Sawing and cleaving the gems is used during the polishing phase. The modern diamond cutter is focused on creating the best, most flawless diamond in the industry to get maximum economic profits. The cutter must first analyze each diamond, by hand, to observe any inclusions. By doing this, the best possible section of the diamond can be utilized when setting in a piece of jewelry. In modern times, lasers have been utilized in diamond cutting whereas other diamonds had to be used in the past. There are several types of faceting that are most popular. Faceting is the process of creating flat faces on geometric shapes. The brilliant cut of diamonds is widely used and has multiple facets (Figure 7). Once properly faceted, the diamond can be set into a desired jewelry piece
A WONDERFUL PROJECT BY GROUP 5 MEMBERS KARAN JARIWALA JUGATI CHALODIA SHREYAS NAIR RIDDHI LADANI YASHASWI KHEMKA RADHIKA GUPTA