THE properties so far considered as serving to recognize valuable stones have all depended
upon the conduct of the material toward light.
These properties were viewed as first since they bear, to those familiar with their utilization,
fast and sure methods for arranging valuable stones.
Thickness of Minerals. We will next think about a similarly certain test, which, nonetheless, requires
Maybe additional time, mechanical assembly, and ability to apply.
Every sort of valuable stone has its own thickness. That is, if bits of various stones were taken
the entirety of a similar size, the loads would vary, yet like-sized bits of one and the same
material consistently have a similar weight. It is the custom among researchers to analyze the densities
of substances with the thickness of water. The number which communicates the connection between the
thickness of any substance and the thickness of water is known as the particular gravity number of the
substance. For instance, if, size for size, a material, say jewel, is 3.51 occasions as weighty as
water, its particular gravity is 3.51. It will be seen that since every substance consistently has, when
unadulterated, a similar explicit gravity, we have here a methods for recognizing valuable stones. It is very
sometimes, if at any point, the case that we track down any two valuable stones of a similar explicit gravity. A couple
stones have almost similar explicit gravities, and in such cases it is well to apply different tests
moreover. Truth be told one ought to consistently ensure a stone by seeing that a few distinct tests
highlight similar species.
We should next discover how to decide the particular gravity of a valuable stone. In the event that the shape
of a stone were to such an extent that the volume could be promptly determined, at that point one could undoubtedly think about
the load with the volume or with the heaviness of a similar volume of water, and in this way get the
explicit gravity (for a particular gravity number truly tells how much heavier a piece of material
is than a similar volume of water).
Tragically the type of most valuable stones is with the end goal that it would be extremely hard to ascertain
the volume from the estimations, and the last would be difficult to make precisely with little
stones. To keep away from these challenges the accompanying shrewd strategy has been concocted:
In the event that a stone is dropped into water it shoves to the side, or uproots, a waterway precisely equivalent in
volume to itself. On the off chance that the water consequently dislodged were gotten and gauged, and the heaviness of the
stone at that point isolated by the heaviness of the water uprooted, we would have the particular gravity
number of the stone.
This is correctly the thing is done in getting the explicit gravity of little stones. To ensure
getting an exact outcome for the heaviness of water uprooted the accompanying device is utilized.
A, Flask-like Bottle; B, Indicates Ground Glass Stopper;
C, Shows Hole Drilled through Stopper.
The Specific Gravity Bottle. A little cup like jug (see Fig. 5) is acquired. This has a firmly
fitting ground glass plug (B). The plug has a little opening (C) penetrated through it longwise. On the off chance that
the jug is loaded up with water, and the plug dropped in and fixed, water will spurt out
through the little opening in the plug. On clearing off plug and container we have the jug
precisely brimming with water. In the event that now the plug is eliminated, the stone to be tried (which should obviously
be more modest than the neck of the container) dropped in, and the plug supplanted, precisely so much
water will spurt out as is equivalent in volume to the stone that was dropped in.
On the off chance that we had gauged the full jug with the stone on the dish next to it, and afterward gauged the jug
with the stone inside it we could now, by deducting the last weight from the principal, discover how
much the water, that was dislodged, gauged. This is exactly the activity. The heaviness of the
stone being realized we currently have simply to separate the heaviness of the stone by the heaviness of the
dislodged water, and we have the particular gravity number. Reference to a table of explicit
gravities of valuable stones will empower us to name our stone. A particularly table follows this exercise.
A Sample Calculation. The real presentation of the activity, in the event that one is gifted in
gauging, takes less time than it would to peruse this portrayal. From the outset one will be moderate, and
maybe one should peruse and re-read this exercise, ensuring that every one of the thoughts are clear previously
attempting to place them practically speaking.