The artists
give the gemstones a definition that: the minerals with multiple color, high
refractive index, great luster, high transparency, good hardness and steady chemical
property can be regarded as gemstones. The most common jewelries in the shops like
the diamonds, ruby, sapphire, and emerald are members of the precious gems. Then
I will give a brief introduction to the gems from the highest grade.
Diamond
It is
the result of adamas after polishing and cutting. It is known as the most
precious gems in the world. The main chemical element is pure carbon and most of
them present light color like transparent, yellow or blue. The hardness is 10;
it says that it is the hardest substance people have found in the earth. As the
high refractive index and strong dispersion, the adamas always been processed into
the diamond with several ridges and surfaces. The more ridges and surfaces, the
brighter gems will be.
Ruby
The ruby is the red corundum crystal, the
hardness is 9. It is the valuable gems rank only secondly to diamond. Because of
the infrequent output, the size above 2 carat can be even rarer.
Sapphire
The blue
corundum crystal, it has richer storage in earth and the big size can be easier
obtained than when compared with ruby. The biggest one in the world is about
900g.
Emerald
It is
the translucence or even transparent beryl with the hardness of 7.5. The high
grade emerald is always pure and clear.
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