Ancient alabaster

The word crystal often meant with the ancients quartz crystal, but it is very evident that with the authors of these notes the term was used in a more comprehensive sense to include other transparent or translucent stones. This use is very evident in the many recipes for imitation of precious stones, where the processes involve a degree of porosity or absorbent power towards colored solutions not possessed either by quartz crystal or by glass, while certain agates, micas, alabasters or other stones possess this property. In case of the above recipe, it is doubtful whether any such mordanting would in a reasonable time roughen the surface of real quartz crystal adequately. The quicksilver here mentioned is evidently the same substance of pearly luster previously referred to. 

Agricola divides the minerals into 1. earths, such as clays, chalks, ochres, etc. 2. stones, properly so called, gems, semiprecious stones. 3. solidified juices, (succi concreti), salt, alum, vitriols, saltpeter, etc. This is an application of the theory of the ancients that these are derived from solidified waters. 4. rocks, such as marble, serpentine, alabaster, limestone, etc., hard and not friable like the earths. 5. metals. 6. compounds, or mixtures, under which head he classes various ores of the metals, from which he recognizes that simpler constituents, as the metals, may be obtained. The fundamental basis of this classification Agricola explains in the following manner.80... 

The plaster found wide application in ancient Egypt [2], It was applied as mortar and to stucco decoration, for example in Tutankhamen s tomb, for firnshing the tombstones of calcite (called alabaster). As mortar it was used in pyramids, in Giza. The beginning of its application is not establish it is regarded that it falls in the period from 5,000 to 3,400 year before Christ [2], The plaster application, instead of lime Jaworski explains by the lack of fuel, because the limestone are more easily accessible than gypsum raw materials [2]. 

Alabaster The massive fine grained granular compact type the name is related to a place in ancient Egypt called Alabaston, where this mineral used to be quarried for sculpturing (it is not known for certain whether the name of the place was after the name of the mineral or the other way around). 

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