A bund consists of: an impervious bund wall or embankment surrounding the facility or tanks. an impervious floor within the bunded area. any joints in the floor or the wall, or between the floor and the wall.
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Turquoise varies in quality from Gem quality to low grade âchalkâ. 1  GEM quality turquoise is HARD. 2  LOW grade turquoise is SOFT.  Turquoise is a hydrated phosphate of copper and aluminum and is formed by the percolation of meteoric or groundwater through aluminous rock in the presence of copper. For this reason, it is often associated with copper deposits as a secondary mineral. Turquoise is most often found in arid, semiarid or desert places.