It is sad to admit, but many Jewelers & Antique Dealers
who handle diamonds on a regular basics, interchange
the two "names" without truly
understanding the difference between these two styles of
cutting, and their many "transitions" along
the way. Starting with the "Old Mine Cut", with its
square shape and slowly changing to the "Old
European Cut" with its round shape. By
studying the cutting style of
the diamond, one can determine the
actual circa (with in a few years), that the diamond was
actually cut from the rough. The descriptions below will
give you a better understand these differences.
q Old Mine Cut = Square in
shape, small table, no point on the culet & could be
off center. That is to say that the cut diamond
generally has the same shape as the original crystalline
structure of the diamond when it was in the rough,
(Rather square in appearance)
q Late Transitional Old Mine Cut
= The same as above but with some rounding
of the girdle, small table, no point on the culet and it
may or may not be centered, (Getting
a bit rounder, but still somewhat square)
q Early Transitional Old European Cut
= Almost a round girdle but not perfectly round at
this point,
small table, no point on the culet and almost centered.
That is to say that this diamond has all the
cutting characteristic of an Old European Cut Diamond,
except that it is not fully round, as an Old
European Cut should be. The girdle
“almost round”, but it shows a bit of the
“square ness” that is normally associated with an
Old Mine Cut Diamond. Thus its classification is an Early
Transitional- Old European Cut, a period of
cutting and time when diamond cutting was making the
transition from Old Mine Cut to Old European Cut.
("Almost Round, but not actually round")
q Old European Cut = A round
girdle, small table, no point on the culet and it should
be relatively centered. (At last
the Diamond is Round)
q Late Transitional Old European Cut
= A round girdle, the table is getting wider, and
the culet may have a point or almost a point and be
centered. The transition of cutting is approaching the
modern brilliant cut, but the diamond does not
have the mathematical proportions to be classified as a
modern brilliant cut, a period
of cutting and time when diamond cutting was making the
transition from Old European Cut to an Modern Brilliant
Cut. (Round, and the table is
still a bit small)
q
Modern Brilliant Cut = A
round girdle, the depth is 57.0 to 63,0%, the table is a
53.0 to 66.0 % of the width, the pavilion depth is 41.5
to 45.5%, the crown height should be 11.0 to 16.2% of
the overall depth, and the crown angle is 30.0 to 35.0
degrees. There should be a good point on the girdle and
it should be centered.
(Gemological Cutting Perfection)
~~~~~ ~~~~~
~~~~~ ~~~~~
Another basic
explanation:
Old Mine Cut Diamond
1. If the diamond has
a somewhat square shape and the culet (the
diamond point) does not come to a point it is an
Old Mine Cut Diamond.
Old European Cut Diamond
2. If the diamond has a round
shape, with a small table and the culet
(the diamond point) does not come to a point, it
is a Old European Cut Diamond.
~~~~~ ~~~~~
~~~~~ ~~~~~
An easy way to
remember:
-
Square=OMC
-
Round= OEC
~~~~~ ~~~~~
~~~~~ ~~~~~
I hope the above explanation is helpful in understanding
the difference between these two diamond cutting styles
that relate directly to the period of when a particular
diamond was cut. With this knowledge, one can
properly assign an proper circa for that particular
diamond. Since diamonds in many cases are re-set
into other pieces of jewelry, as a result there are
times when an item can have several different ages
assigned to that same item of jewelry.
Example: Multiple periods
"The major 1.00 ct. Old-Mine-Cut Diamond, circa
1880's, and the ring circa 1920", thus there
positive indication that this "older-cut-diamond" was
re-set into a newer style ring thirty years later.
Likewise sixty years later, someone's granddaughter
could have the same diamond re-set again into a more
up-to-date ring mounting. Consequently any qualified
appraiser should not only evaluate the age of the
gemstones, but they should have vast understanding of
the various motifs, findings, manufacturing methods
ect., that relate to a particular style of jewelry when
assigning a proper circa for that item. All of these
indicators are there "speaking" to the
appraiser, as one views that item of jewelry, but more
importantly it is the knowledge and comprehension of
what these indicators are telling you, that is critical
when assigning a proper circa for a particular item of
jewelry.
Walt Tofel
"Your Master Jeweler"
