

The word Gemology (Gemmology) is a branch of mineralogy. It refers to the study of a gem by a Qualified Gemologist. There are ‘n’ numbers of minerals on the earth but only a few of them are considered as ‘GEMS’ on the basis of B, R and D.
B stands for ‘Beauty’,
R stands for ‘Rarity’ and
D stands for ‘Durability’.
Any mineral which is beautiful but rare, not easily available, and has enough durability to resist normal wear and tear is qualified as a gem. there are few exceptions like the stone Chalcedony and marble.
So, you might be thinking of the word ‘Gem’ and the word ‘Gemstone’ is exactly the same?
The answer is NO.
Gems are categorized into two categories : organics and inorganic.

The word GEM is used for both the categories of stones whether the material is organic like pearl and coral or inorganics like Quartz and Topaz. But,

The word GEMSTONE is used only for the inorganic materials like Sapphire, emeralds etc.
So,
Without understanding the word “Gem or gemstone” and the word “Gemologist”, it is impossible to understand the phrase Gemology.
So, what is Gemstone?
A gemstone is a solid substance, made in nature, having a definite chemical composition and crystalline in nature, which can be cut/polished from a rough form.
What is the meaning of Gemologist?
A Gemologist is a specialist in gems; precisely: one who knows all the aspects of identifying a Gem.
Now, we know the word Gemology: means a study of Gemstones by a Gemologist.
A gemologist identifies a gemstone by looking up the following characteristics
Colour, phenomenon, Pleochroism, Refractive index, Specific gravity, Hardness, Optic character, Spectrum, Fluorescence and Phosphorescence, Inclusions, Fracture, Cleavage, Crystallographic features, Dispersion
Let’s have a look upon the instruments through which these properties are analyzed.

The phenomenon is checked with bare eyes under incandescent light.

Refractive index is checked with the help of Refractor meter

Pleochroism is checked with both bare eyes and with the help of dichroscope
Different instruments are used to check different properties.

Specific gravity is checked with the help of SG Kit or SG liquid

Hardness is checked by scratching the stones with hardness scale penile

Optic character is checked with the help of Polariscope

Spectrum is checked with the help of a spectrometer
Spectrum is checked with the help of a spectrometer

Short wave and long wave ultraviolet is used to check fluorescence and Phosphorescence

10x eye loupe and Microscope is best to view Inclusions
What a material of un-ambiguity and preserveness of valuable familiarity regarding unexpected feelings. Mame Conny Wiersma
Your way of describing all in this article is actually nice, every one be able to easily be aware of it, Thanks a lot. Phillis Bertrando Idette