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Bort, boart, or boort is an umbrella term used in the diamond industry to refer to shards of non-gem-grade/quality diamonds.In the manufacturing and heavy industries, "bort" is used to describe dark, imperfectly formed or crystallized diamonds of varying levels of opacity.
The precise tensile strength of diamond is unknown, though strength up to 60 GPa has been observed, and theoretically it could be as high as 90–225 GPa depending on the sample volume/size, the perfection of diamond lattice and on its orientation: Tensile strength is the highest for the [100] crystal direction (normal to the cubic face ...
The term is based on the word "whet", which means to sharpen a blade, [2] [3] not on the word "wet". The verb nowadays to describe the process of using a sharpening stone for a knife is simply to sharpen, but the older term to whet is still sometimes used, though so rare in this sense that it is no longer mentioned in, for example, the Oxford Living Dictionaries.
The clarity, or purity, of a diamond refers to internal inclusions of the diamond, and is one of the 4-Cs in determining a diamond's value.Common inclusions that appear inside diamonds are black carbon spots and small cracks, commonly referred to as fractures or "feathers", due to their feathery whitish appearance when viewed from above or through the side.
A surface grinder is a machine tool used to provide precision ground surfaces, either to a critical size or for the surface finish. The typical precision of a surface grinder depends on the type and usage, however ±0.002 mm (±0.0001 in) should be achievable on most surface grinders.
The kerf, or width, of the cut can be adjusted by swapping parts in the nozzle, as well as changing the type and size of the abrasive. Typical abrasive cuts have a kerf in the range of 0.04 to 0.05 in (1.0–1.3 mm), but can be as narrow as 0.02 inches (0.51 mm).
Generally, honing grains are irregularly shaped and about 10 to 50 micrometers in diameter (300 to 1500 mesh grit). Smaller grain sizes produce a smoother surface on the workpiece. A honing stone is similar to a grinding wheel in many ways, but honing stones are usually more friable, so that they conform to the shape of the workpiece as they ...
[4] [5] [6] The double diamond drill technique was present in Western India prior to 600 BC (7th century BC). [7] There is also evidence of technique of double diamond drilling from Southern Thailand dating back to 400 BC. [8] Before diamonds were discovered in Brazil in the 1700s, India was the only place where diamonds were mined.