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.
Find great deals on eBay for turquoise slabs and turquoise rough. Shop with confidence.
Lastly there is one way to tell if your Turquoise is natural or dyed. That is the price. If it seems too good to be true, then it probably is. Take for example a strand of perfectly matching amazing blue Turquoise beads. In nature it would be very difficult to find a bunch of Turquoise beads that have exactly the same color. The biggest piece of advice to give when buying Turquoise is to try and find someone you trust. Ask them where the stones come from, get a feel for how much knowledge they have.