Emeralds are gem-quality specimens of the beryl mineral family with a rich, distinctly green color. They are found in igneous, metamorphic, and sedimentary rocks in a small number of locations worldwide. For over 5000 years, emeralds have been one of the most desirable and valuable colored gemstones.
For example, the Agway Elevator was built on a concrete mat 3 feet thick which in turn rests on a natural foundation of stiff clay. But whatever the foundation for the elevator was, be it wood pilings or concrete slabs, construction of the elevator itself could begin once the base was completed.
Basically a mining elevator can be seen on figure 3. . Fig. 1 A circular mine shaft. Suspension ropes are enwrapped around a drum and. counterweight is attributed to the end of the suspension rope and the. other end is connected to the car.