U.S. patent application number 12/896105 was filed with the patent office on 2012-04-05 for gem with brilliant cut.
Invention is credited to Guenther BLASBICHLER, Karlheinz Eder, Markus Sauer.
Application Number | 20120079853 12/896105 |
Document ID | / |
Family ID | 44773934 |
Filed Date | 2012-04-05 |
United States Patent
Application |
20120079853 |
Kind Code |
A1 |
BLASBICHLER; Guenther ; et
al. |
April 5, 2012 |
GEM WITH BRILLIANT CUT
Abstract
Brilliant-cut gemstone, wherein the crown angle (.alpha.) is
between 32.8.degree. and 33.0.degree..
Inventors: |
BLASBICHLER; Guenther;
(Innsbruck, AT) ; Eder; Karlheinz; (Buch in Tirol,
AT) ; Sauer; Markus; (Mils, AT) |
Family ID: |
44773934 |
Appl. No.: |
12/896105 |
Filed: |
October 1, 2010 |
Current U.S.
Class: |
63/32 |
Current CPC
Class: |
A44C 17/001
20130101 |
Class at
Publication: |
63/32 |
International
Class: |
A44C 17/00 20060101
A44C017/00 |
Claims
1. Brilliant-cut gemstone, characterized in that the crown angle
('') is between 32.8E and 33.0E.
2. Gemstone as claimed in claim 1, characterized in that the
pavilion angle ($) is between 41.7E and 41.9E.
3. Gemstone as claimed in claim 1, characterized in that the
gemstone (1) is comprised at least to a large part, preferably
entirely, of cubic zirconia.
4. Gemstone as claimed in claim 1, characterized in that the angle
between the girdle plane (7) and those pavilion facets (8), which
have a point disposed in the direction toward the girdle (4), is
between 41.7E and 41.9E, and/or the angle between the girdle plane
(7) and those pavilion facets (9) which border with a broadside on
the girdle (4) is between 42.8E and 43.0E.
5. Gemstone as claimed in claim 1, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
6. Gemstone as claimed in claim 2, characterized in that the
gemstone (1) is comprised at least to a large part, preferably
entirely, of cubic zirconia.
7. Gemstone as claimed in claim 2, characterized in that the angle
between the girdle plane (7) and those pavilion facets (8), which
have a point disposed in the direction toward the girdle (4), is
between 41.7E and 41.9E, and/or the angle between the girdle plane
(7) and those pavilion facets (9) which border with a broadside on
the girdle (4) is between 42.8E and 43.0E.
8. Gemstone as claimed in claim 3, characterized in that the angle
between the girdle plane (7) and those pavilion facets (8), which
have a point disposed in the direction toward the girdle (4), is
between 41.7E and 41.9E, and/or the angle between the girdle plane
(7) and those pavilion facets (9) which border with a broadside on
the girdle (4) is between 42.8E and 43.0E.
9. Gemstone as claimed in claim 2, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
10. Gemstone as claimed in claim 3, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
11. Gemstone as claimed in claim 4, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
12. Gemstone as claimed in claim 6, characterized in that the angle
between the girdle plane (7) and those pavilion facets (8), which
have a point disposed in the direction toward the girdle (4), is
between 41.7E and 41.9E, and/or the angle between the girdle plane
(7) and those pavilion facets (9) which border with a broadside on
the girdle (4) is between 42.8E and 43.0E.
13. Gemstone as claimed in claim 7, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
14. Gemstone as claimed in claim 8, characterized in that the angle
between the girdle plane (7) and those crown facets (10), which
border with a broadside on the table (5), is between 20.2E and
20.4E and/or the angle between the girdle plane (7) and those crown
facets (11) which have a point bordering on the girdle (4) is
between 32.8E and 33.0E and/or the angle between the girdle plane
(7) and those crown facets (12) which border with a broadside on
the girdle (4) is between 39.3E and 39.5E.
Description
[0001] To increase the brilliance of a faceted cut gemstone,
diverse types of cuts have been developed over time, which, on the
one hand, differ by the number of facets and, on the other hand, by
the mutual geometric relationships of the facet positions.
[0002] The so-called brilliant cut has been found to be especially
esthetic in particular for diamonds since this cut critically
impacts the so-called "fire" of the diamond, which fire is based on
numerous internal light reflections. These light reflections occur
at the individual facets which have special angular relations with
one another characterizing the particular cut. Consequently, the
cut of a gemstone, especially that of a diamond, is decisive for
the generated fire.
[0003] Further parameters characteristic of the esthetics of a
gemstone, that are dependent on the particular cut, are the
scintillation describing the sparkle of a moved gemstone and the
brilliance describing the brightness and the contrast of the light
exiting from a gemstone. A diamond with a brilliant cut is
generally also referred to as a brilliant.
[0004] A gemstone with brilliant cut includes a crown, also
referred to as the top part, with at least 32 facets and a table,
as well as a pavilion, also referred to as the bottom part, with at
least 24 facets. The end opposite the table of the gemstone can be
formed as a point or as a rounded-off point in the form of a
so-called culet. Between top and bottom part is disposed the
so-called rondiste or girdle. The gemstone is cut
symmetrically.
[0005] The invention addresses the problem of further improving the
esthetic impression of a gemstone with brilliant cut, for example
providing increased luminous efficiency or increased luminance or
brightness.
[0006] This is resolved in a gemstone with the features of claim
1.
[0007] Thereby that the gemstone has a brilliant cut in which the
crown angle is between 32.8.degree. and 33.degree., an especially
high luminous efficiency was unexpectedly obtained, whereby the
fire, the scintillation and the brilliance of the gemstone are
being brought out especially well.
[0008] The crown angle is that angle which, in a side view of the
gemstone, is formed between the lateral boundary line of the crown
and the girdle plane, wherein this boundary line results by
orthogonal projection of a crown facet onto a plane containing the
longitudinal axis of the gemstone.
[0009] The girdle plane is that plane which is located parallel to
the table and in which the gemstone has its greatest
cross-sectional dimension. The girdle plane is oriented
perpendicularly to the longitudinal direction of the gemstone.
[0010] To measure the luminous efficiency or brightness of the
gemstone, which efficiency corresponds to a reflected light
fraction, measurements are carried out using an illumination
arrangement and measuring specifications developed by the
Gemological Institute of America (GIA). The corresponding measuring
specifications are found in the magazine "Gems & Gemology",
Fall 2004, pp. 202-228, in which, in particular on page 219, a
measuring arrangement for measuring the brightness of a gemstone is
depicted. Instead of an actual measurement, the measurement can
also be computationally simulated based on the geometry of the
gemstone. The measurement or the results of the simulation yield
values for several characteristic light- or radiation-specific
parameters of the gemstone, in particular brightness and/or
luminous efficiency.
[0011] The gemstone located in the center of the base circle is
illuminated using a hemispherical illumination arrangement with
directed irradiation normal to the surface. The illumination
arrangement generates a Lambert beam distribution with sufficiently
large sectional angle such that lateral facets of the gemstone are
also illuminated. The quantity of light reflected by the gemstone
represents a mean value over nearly all possible illumination
configurations and consequently provides a quantitative measure of
the luminous efficiency or the brightness of the gemstone. The
higher the fraction of the reflected or backscattered light, the
higher is the light efficiency and the brightness and the better is
the reflection behavior of the gemstone, which is accompanied by
esthetic perceptions of higher value.
[0012] To measure the reflected or backscattered light serves a
photo-current detector at a very large distance, relative to the
dimensions of the gemstone, with a narrow measuring field.
[0013] Further advantageous embodiments of the invention are
defined in the dependent claims.
[0014] In a preferred embodiment the pavilion angle is between
41.7.degree. and 41.9.degree..
[0015] The pavilion angle is that angle formed, in a side view of
the gemstone, between the lateral boundary line of the pavilion and
the girdle plane, wherein this boundary line is obtained by
orthogonal projection of a pavilion facet onto a plane including
the longitudinal axis of the gemstone.
[0016] Although the gemstone according to the invention can be
produced of any desired natural or synthetic precious or
semiprecious stone, a gemstone of glass or synthetic material with
the brilliant cut according to the invention is also feasible.
[0017] It was herein unexpectedly found that an especially high
luminous efficiency is realizable at a crown angle between
32.8.degree. and 33.degree. and/or at a pavilion angle between
41.7.degree. and 41.9.degree. if the gemstone is comprised at least
to a large extent, preferably entirely, of cubic zirconia.
[0018] The pavilion, also known as bottom part, has at least 24
pavilion facets, which come together at the end opposite the table
in the form of a point or a culet. In one embodiment eight pavilion
facets have a point located in the direction toward the girdle,
while 16 pavilion facets have a broadside bordering on the girdle.
The end located opposite the broadside of these pavilion facets
forms a point and is directed away from the girdle. The orthogonal
projection of the last-cited pavilion facets yields the pavilion
angle.
[0019] In one embodiment of the invention the angle between the
girdle plane and those pavilion facets that have a point bordering
on the girdle or located in the direction toward the girdle, is
between 41.7.degree. and 41.9.degree.. Additionally or
alternatively, it can be provided that the angle between the girdle
plane and those pavilion facets that have a broadside bordering on
the girdle is between 42.8.degree. and 43.0.degree..
[0020] The crown of the gemstone, also known as the top part,
includes a table which is bordered by eight crown facets with one
broadside each. In one embodiment of the invention these crown
facets form with the girdle plane an angle between 20.2.degree. and
20.4.degree..
[0021] The crown includes furthermore sixteen crown facets which
have a point bordering on the girdle. In one embodiment of the
invention these crown facets form with the girdle plane an angle
between 39.3.degree. and 39.5.degree..
[0022] The crown includes furthermore eight additional crown
facets, each of which borders with a broadside on the girdle. In
one embodiment of the invention the angle between these crown
facets and the girdle plane is between 32.8.degree. and
33.0.degree.. The orthogonal projection of the last cited crown
facets forms the crown angle.
[0023] Further details and advantages of the present invention will
be explained in further detail in conjunction with the description
of the figures with reference to the drawing. Therein depict:
[0024] FIG. 1a to 1c a side view, a top view as well as a view from
below onto a gemstone according to the invention,
[0025] FIG. 2 a schematic representation regarding the definition
of the crown angle and of the pavilion angle,
[0026] FIGS. 3a and 3b a comparison of a gemstone of prior art with
a gemstone according to the invention using a schematic depiction
of paths of rays,
[0027] FIG. 4 a schematic depiction of the measuring arrangement
for measuring the luminous efficiency or brightness.
[0028] FIG. 1a shows a gemstone 1 according to the invention in a
side view. Evident is the girdle 4, which separates the crown 2,
also referred to as the top part, from the pavilion 3, also
referred to as the bottom part. The girdle 4 is the region of the
greatest cross-sectional dimension of the gemstone 1. Schematically
shown is furthermore the axis of symmetry of the gemstone in the
longitudinal direction which corresponds to the longitudinal axis
of the gemstone.
[0029] The pavilion 3 has two types of pavilion facets 8, 9. Herein
sixteen pavilion facets 9 include a broadside with which these
facets border on the girdle 4. At the opposite end the pavilion
facets 9 come together in the form of a point in the direction
toward the culet 6. The remaining pavilion facets 8 include a
point, each of which borders on the girdle 4.
[0030] The crown 2 comprises 32 facets 10, 11, 12 as well as a
table 5 oriented parallel to the girdle plane 7.
[0031] Sixteen crown facets 12 border with one broadside on the
girdle 4 and have a point directed in the direction of the table 5.
Eight further crown facets 10 border with one broadside each on the
table 5. The remaining eight crown facets 11 have each a total of
four points, of which one point borders on the table 5, while
another point borders on the girdle 4.
[0032] Evident is also the lateral boundary line 16 of crown 2,
which is formed as the orthogonal projection of the crown facets
12, and the lateral boundary line 17 of the pavilion 3 formed as
the orthogonal projection of the pavilion facets 9.
[0033] In one embodiment example of the invention the gemstone 1 is
comprised of cubic zirconia and has a crown angle .alpha. between
the lateral boundary line 16 and the girdle plane 7 of 32.9.degree.
and a pavilion angle .beta. between the lateral boundary line 17
and the girdle plane 7 of 41.8.degree.. The angle between the
girdle plane 7 and the crown facets 12, which border with their
broadside on the girdle 4, is 39.4.degree.. The angle between the
girdle plane 7 and those crown facets 10 which border with their
broadside on the table 5, is 20.3.degree.. The angle between the
girdle plane 7 and the remaining crown facets 11 is 32.9.degree..
The angle between the girdle plane 7 and the pavilion facets 9,
which border with their broadside on the girdle 4, is 42.9.degree..
The angle between the girdle plane 7 and the remaining pavilion
facets 8 is 41.8.degree..
[0034] FIG. 1b depicts a top view onto the crown 2 of the gemstone
1. The schematically shown rectangular coordinates on table 5 make
evident the symmetry of the gemstone 1.
[0035] FIG. 1c depicts a view from below onto the pavilion 3 of the
gemstone 1. On the culet 6 formed by the pavilion facets 8
bordering on one another, is symbolically depicted a further
rectangular coordinate system to illustrate the symmetry of the
gemstone 1.
[0036] FIG. 2 shows a schematic depiction to explain the crown
angle .alpha., which is formed between the girdle plane 7 and the
lateral boundary line 16 of crown 2, while the pavilion angle
.beta. is formed between the lateral boundary line 17 of pavilion 3
and the girdle plane 7.
[0037] FIG. 3a shows a gemstone 1' with brilliant cut according to
prior art. The light rays 13 entering the gemstone are only
partially reflected on pavilion 3' due to the angles at which the
different pavilion facets are cut, in particular due to the crown
angle and to the pavilion angle. A fraction of the rays exits from
the pavilion 3' in the form of refracted rays 14. The ratio of the
light rays 15 exiting from the crown 2' to the light rays 13
entering into the crown 2' defines the luminous efficiency.
[0038] FIG. 3b shows the same depiction but of a gemstone 1
according to the invention. The luminous efficiency is markedly
improved due to the specific geometric configurations of the
different facets and of the crown angle a.alpha. and of the
pavilion angle .beta.3, since the majority of the rays is totally
internally reflected in the region of pavilion 3 such that nearly
the entire fraction of light rays 13 entering the crown 2, after
possibly multiple reflections, is reflected back to the viewer in
the form of light rays 15 exiting from the crown 2.
[0039] FIG. 4 shows in schematic view a measuring arrangement for
measuring the brightness or luminous efficiency of a gemstone
employing the measuring specifications of the cited article in the
magazine "Gems & Gemology". Using a hemispherical illumination
arrangement 16 a gemstone 1, located in the center of a base circle
17 of the hemisphere 16, is illuminated by light rays 18 such that
the crown 2 of the gemstone 1 is irradiated with white diffuse
light, wherein the light beams, except for a shielded region 19,
impinge hemispherically onto the gemstone 1 and are reflected at
it. Except for a recess for the gemstone 1, the base circle 17 is
shielded such that no light impinges on the gemstone 1 from below
the base circle 17. Also shielded is a region 19 of the hemisphere
16, which is precisely opposite the gemstone 1 and has an aperture
angle .alpha. of 46.degree.. From this region there is also no
light reaching the gemstone 1. The region 19 includes a recess 20
with an angle of aperture .beta. of 3.degree.. This recess 20
serves as the measuring field for a detector. Consequently, above
the recess 20 a detector measuring a photo current can be disposed.
Instead, the particular light-specific values, such as for example
the brightness, can be calculated in the region of this recess 20
in a computer simulation.
[0040] The quantity of light reflected by the gemstone 1 represents
a mean value over nearly all possible illumination configurations
and consequently yields a quantitative measure of the luminous
efficiency or the brightness of the gemstone 1. The reflections
occur herein on distinct facets such that light is directly
reflected back to the recess upon the first impingement onto the
gemstone, however also after several internal reflections.
* * * * *