| The
first normal standard clarity grading recognised the
world over was introduced by the GIA in America at the
end of the 1920s. Also the 10 times loupe was also recognised
as the magnification used to grade diamonds. This was
needed to be able to recognise diamonds and sell diamonds
by description and make it easier to trade.
Inclusions
have 3 different phases of growth.
1). Inclusions
present before the crystallisation. (Preexisting inclusions)
2). Inclusions
formed at the same time as the diamond. (Syngenetic
inclusions)
3). Inclusions
formed after crystallisation. (Epigenetic inclusions)
Cracks & other inclusions formed in the cooling
of the diamond.
In America a Flawless diamond is
a diamond that is flawless internally and externally
any negligible features that could easily be removed
by polishing are ignored. So they have 2 grades F flawless
and IF internally flawless.
In Europe F flawless is only graded
on the internal properties of the stone. So a diamond
in Europe that is internally flawless is classed as
F flawless.
F =
Flawless
VVS1 = very very small inclusions and
not many.
VVS2 = very very small inclusions.
(This subgroup is only used in stones of .47 points
and over.)
VS1 = very small inclusions and not
many.
VS2 = verysmall inclusions. (This subgroup
is only used in stones of .47 points and over.)
SI1 = small inclusions and not many.
SI2 = small inclusions. (This subgroup
is only used in stones of .47 points and over.)
P1 or I1 = included can be seen by
the naked eye.
P2 = included can be seen by the naked
eye plus very obvious.
P3 = included can be seen by the naked
eye extremely obvious.
All these grades
are graded by looking in the diamond from different
angles. But the final grading is done looking straight
down on the table and it is the look of each inclusion
at this angle that decides the grade. You could have
exactly the same mark in 2 diamonds and if 1 mark was
in the centre of the table and in the other diamond
the same mark was on the outside of the stone they would
be 1 grade apart.
Also say a fracture or cleavage
mark was the same size in 2 diamonds and you could see
the whole mark while looking into the table in 1 diamond
and in the other diamond you could only see the side
of the mark these would be 2 different grades.
It is not that easy the grades depend on the size the
position the amount the colour and type of inclusions.
You cannot possibly look at a small picture and be able
to know the grade. If you look through a 10 times loupe
not a 3 times or any other. (This will be marked on
the loupe 10 times). You will not be able to see a vvs
inclusion and you would see a vs inclusion but you will
have to look properly. It is not that easy to use a
10 times loupe to start with. A si inclusion would be
relatively easy to see in the stone and can be a small
black mark or slightly larger white mark or feather/crack.
You must remember you are looking through a 10 times
loupe and the size of a SI inclusion can look quite
large through this. Take the loupe away and see if you
can see the inclusion with your naked eye if you cannot
it is a SI stone.
The size and position of all marks
is relative to the stone and relative to whether you
can see the mark by eye without the loupe.
Grading diamonds is very hard it
is not something that can be easily learnt if you know
someone you confident with use him or her. If you are
not sure get an expert. I have a lot of stones I would
not sell these days bought when I first started. (These
are still better than the high street quality but I
only sell the very best diamonds now.) These will go
to auction and I will get my money back because even
then I knew a bit more than most people. I did not buy
wrongly but if you are buying 1 stone use someone that
knows and will guarantee his or her choice it is not
worth the risk not to.
You may think you
are getting a lot more for your money but 99% of the
time you are not. My job and my passion are diamonds
and I have got it wrong in the past. Every day we all
learn more but unfortunately it costs money learning.
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I will now list the types
of internal flaws that can be seen. |
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Group of pinpoints |
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Light pinpoint inclusion |
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Dark spot |
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Group of dark spots |
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Cloud of light tiny
pinpoints |
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Colourless crystal |
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Group of colourless
crystals |
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Cleavages around a colourless
crystal |
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Large black or coloured
inclusion |
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Blow indentation |
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Dark or coloured inclusion |
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surrounded by a cloud |
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Small cleavage, tensions or fracture
crack |
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Large cleavage, tension or fracture
crack |
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Bearded girdle (Tiny cleavages penetrating
inside the stone.) |
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Girdle cleavage surrounded by a cloud |
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Growth or twinning line or twinning
planes colourless reflection |
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Growth or twinning line or twinning
planes coloured |
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Larger natural with trigons |
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Natural set into girdle |
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External features.. |
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Small natural |
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Larger natural with
trigons |
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Natural set in girdle |
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Nick in the girdle |
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Negligibly rough girdle |
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Rough girdle |
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Bearded girdle as external
feature |
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Group of tiny cavities
on the facet |
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Larger cavity hole |
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Nick |
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Polishing marks |
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Blow mark |
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Growth or twinning lines |
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Rough unpolished culet |
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Damaged culet or point |
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Additional extra facet
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Roughened facet edge |
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If you would like
to know more or you have seen a diamond that you have
a close up picture of and you would like me to look
at please e mail me and I will be happy to do so. (Please
do not e-mail the picture in the first instance). The
easiest thing is if someone has told you a diamond is
a certain type ask him or her to send it of to an independent
lab and have it certificated. Tell them you are quite
happy to pay the extra cost if not don’t buy the
stone.
If you would like to know more I
am writing a book. At present and it should be ready
in a few years you can reserve a copy or if you have
a specific question please e-mail me. I will try to
reply as soon as I am able. Normally on a weekend as
I am very busy during the week.
Thank you for your time and
I hope you will choose wisely
Yours Faithfully Jeremy Fischer.
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