FACETIPS A simple Emerald Cut
Duncan Miller
The Emerald Cut is not a meetpoint design so cutting stones with repeatable proportions and facet widths involves guesswork. The following sequence for cutting pavilion and crown avoids most of the guesswork and enables you to cut pairs or sets of matched stones. This sequence is modified from FACET DESIGN Vol. 4 by Robert Long & Norman Steel, in turn based partly on FACETING FOR AMATEURS by Glenn & Martha Vargas. This example uses 5° steps for the three pavilion tiers, but you can use any equal steps up to 10° (say 41°, 51°, 61°) to match the RI and depth of the stone.
1 & 2: Establish desired length and width at 90° by direct measurement.
3 & 4: Cut four keel facets at culet angle (say 40°) to create level temporary girdle.
5 & 6: Cut four break facets at highest angle (say 50°) to equal width in plan-view (guesswork or finicky measurement here).
7 & 8: Cut four intermediate main facets at angle midway between the two previous tiers (say 45°) to create steps of equal width.
9: Cut four corner main facets at intermediate angle (say 45°) to meetpoint of 3,4,7,8.
10: Cut four corner break facets at break angle (say 50°) to meetpoint of 5,7,9.
11. Cut four facets at 90° to level girdle.
The pavilion has been
cut first and the stone transferred to cut the crown. This example uses 40°
main facets but you can use any combination of mains +15° and mains -15° for
the tiers of crown facets.
3 & 4: Cut four main facets (say 40°) to corner meetpoint. This establishes the width of 1 & 2 without guesswork.
5: Cut four corner break facets (55°) to level girdle.
6: Cut four corner main facets (40°) to meetpoint 1,3,5,6.
7, 8 & 9: Cut eight facets at mains -15° (say 25°) until mains and breaks are equal width in plan-view (guesswork or very finicky measurement here).
10: Cut table facet at 0° to preferred size, or until 7, 8 & 9 look nice and narrow.
Two Zambian emeralds Duncan cut recently; 2.86 ct (10.09 ct rough) and 2.49 ct (10.60 ct rough)
In : Faceting
