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However, today's mining and assaying allows the delineation of lower-grade bulk tonnage mineralisation, within which the gold is invisible to the naked eye. In these cases, veining is the subordinate host to mineralisation and may only be an indicator of the presence of metasomatism of the wall-rocks which contains the low-grade mineralisation.
In metallurgy a veining (or finning) is the occurrence of a sheet like casting defect, produced by molten metal penetration into a sand casting mould. Veining a defect on the surface of a casting appearing as fins, veins or wrinkles and associated with excessive thermal movement of the sand, especially core sand
Veins (/ v eɪ n /) are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart.Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart.
Backstamp A small mark applied to the underside, the back, of articles to give information such as the identity of maker. Various techniques to apply the stamp exist.
A casting defect is an undesired irregularity in a metal casting process. Some defects can be tolerated while others can be repaired, otherwise they must be eliminated. They are broken down into five main categories: gas porosity, shrinkage defects, mould material defects, pouring metal defects, and metallurgical defects.
Rosewood is any of a number of richly hued hardwoods, often brownish with darker veining, but found in other colours. [1] It is hard, tough, strong, and dense. True rosewoods come from trees of the genus Dalbergia, but other woods are often called rosewood. Rosewood takes a high polish and is used for luxury furniture-making, flooring, musical ...
Wood grain is the longitudinal arrangement of wood fibers [1] or the pattern resulting from such an arrangement. [2] R. Bruce Hoadley wrote that grain is a "confusingly versatile term" with numerous different uses, including the direction of the wood cells (e.g., straight grain, spiral grain), surface appearance or figure, growth-ring placement (e.g., vertical grain), plane of the cut (e.g ...
Sanidine is the high temperature form of potassium feldspar with a general formula K(AlSi 3 O 8). [2] Sanidine is found most typically in felsic volcanic rocks such as obsidian, rhyolite and trachyte.