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The Nassak is one of those unfortunate Mogul-cut stones
that has been recut to more modern tastes. First recorded history shows
it as a triangular shaped stone of approximately 90 carats. It was then
recut to an 80 carat version, still triangular but with more rounded
corners. It still didn’t meet the changing tastes of history, and was
recut in the 20th century into a 43 carat rectangle.
My research has turned up just one reference of the 90
carat version, and that is in Bauer’s book. His book was first published
in 1904, so he lived at the same time this version existed and may have
actually seen it. Unfortunately, there is no second pictorial reference,
so his version must be assumed to be correct. This is the version seen
on this site.
90 carat version of the Nassak according to Bauer
CZ
replica based off of Bauer’s drawings
This is one of those stones where cutting directions had
to conflict with the source data (the drawing). Not all facets as shown
in the drawing can be cut. The most obvious is the horizontal pavilion
facet in the drawing above. Any stone cutter can see that the facets
above and below this step cut must use index settings either side of the
step cut setting. However, if this is to happen, then the horizontal
facet must taper, rather than have perfectly parallel sides. This
situation is mathematically unresolvable. When this discrepancy occurs
on other stones, what has happened is that the differences between index
settings are so small as to be minute. A small taper exists in reality,
but the drawing will show parallel lines. In this replica, the one
horizontal facet is split into two using two slightly different index
settings.
GemCAd version of the pavilion
There were a few more facets in the replica that differed
from the drawing due to geometry problems. These are also above the
culet in the drawing, and I leave it to others to discover these. I
believe they were in the original stone, but I’ve not been able to fit
them into this GemCad version. (I’ll leave it to challenge others to fit
them in as an academic exercise.) These differences do not
significantly change the stone’s appearance, but the replica does differ
from the historical record in this respect. |
