Classifications

• • A—HUMAN NECESSITIES
  • A44—HABERDASHERY; JEWELLERY
  • A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
  • A44C17/00—Gems or the like
  • A44C17/001—Faceting gems

Definitions

• the present invention relates to a precious stone, semi-precious or mineral, comprising
• a crown comprising in its center a flat table surrounded by a plurality of crown facets,
• breech comprising an acute Colette and several breech facets, and - between the crown and the breech, a belt.
• Such size stones are well known.
• Rock observation devices are also known which make it possible to visualize an image by reflection of light through the diamond under particular lighting conditions (see, for example, JP 6174648).
• the phenomenon known as "arrow” can be observed, that is to say a reflected and distorted projection of the arrangement of the facets is observed.
• breech In a diamond treated to a Round Brillant Cut size, 8 “arrows” will be observed. If we increase the number of veneers, we can observe 10 “arrows” (see for example JP 2004299370).
• This type of size modification does not, however, prevent deformation of the projected image through the crown after reflection of light on the diamond head facets.
• the present invention aims to develop a cut stone does not have this disadvantage and thus allowing an observation of an undeformed image in an observation device according to the prior art.
• the stone thus cut will have an improved gloss and, depending on its size, it will allow the projection of sharp images, different and original.
• a stone as indicated at the beginning wherein said breech facets comprise at least one tip facet which extends between said acute colette and an intermediate location between the belt and the colette .
• said tip facet extends from said acute colette to said intermediate location.
• the tip facets do not extend to the waist. It therefore becomes possible to arrange them so as to be able to observe their image in the observation device according to the state of the art, without deformation, because it can no longer be reflected through facets of the crown, as in FIG. is currently the case with diamonds cut in the usual way.
• a tip facet is, with respect to said colette, located opposite each said tip facet, so that a light projected through said crown at an angle predetermined by relation to the table undergoes a first reflection on a tip facet with projection of an image thereof to said opposite tip facet where the light undergoes a second reflection with projection of said image through the crown, and said intermediate location of each tip facet is disposed between the belt and the Colette so that the image of each peak facet from said second reflection is totally projected perpendicularly through the flat table of the crown.
• the reflected image of the tip facets of the yoke is projected through the crown table, which is quite flat and perpendicular to the reflected rays, thus causing no optical deformation.
• said at least one tip facet extends at an angle of 25 to 52 °, preferably 36 to 41 °, with respect to the table.
• crown facets are arranged under a angle of 25 to 80 °, preferably 33 to 37 ° relative to the table and said tip facets extend at an angle of 40 to 41 ° with respect to the table.
• the present invention also relates to a stone cutting method comprising a faceting of a crown having in its center a flat table surrounded by crown facets, a facetting of a cylinder head having an acute Colette and several facets of cylinder head and a formation of a belt between the crown and the cylinder head.
• This method is characterized in that it comprises a size of at least one breech facet in the form of a tip facet which extends from the acute Colette to an intermediate location between the belt and the Colette.
• Other embodiments of the ashlar according to the invention and its method of size are indicated in the appended claims.
• Figure 1 shows a top plan view of the crown of a diamond according to the invention.
• Figure 2 shows a bottom plan view of the cylinder head of the diamond of Figure 1.
• Figure 3 shows a side view of the diamond of Figure 2, following the arrows HI-III.
• FIG. 4 shows a sectional view along the line IV-IV of the diamond of FIG. 2.
• FIG. 5 shows a view of the tip facets of the diamond head shown in FIGS. 1 to 3.
• Figures 6 and 7 are views similar to Figures 1 and 2, another diamond according to the invention.
• cut diamonds The following description relates to cut diamonds. It should be understood that the present invention also relates to other cut stones, for example rubies, emeralds, etc.
• the illustrated diamond comprises a ring 1 comprising in its center a flat table 2 surrounded by a plurality of crown facets.
• These crown facets are, in the usual way, consisting of eight stars 3, eight bezels 4 and sixteen ring halves 5.
• FIG 2 there is illustrated the cylinder head 6. As shown in Figure 3, it is separated from the ring 1 by a belt 7 or rondiste and it ends in a sharp pointed colette 8.
• the facets of the breech 6 there are four facets which, in this memoir, are called peak facets 9, 10, 11 and 12. These facets extend between the acute Colette 8, in this particular case since the Colette itself, to a location 13, 14, 15 and 16 which is intermediate between the colette 8 and the belt 7. In other words, these tip facets do not extend to the waist, as this is the case of breech facets of cut diamonds in the usual way.
• the other facets of the breech will be called the breeches of breech 17.
• the point facet 9 is longer than the other tip facets 10 to 12 and that together they form a cross with asymmetrical branches.
• a tip facet located opposite to the colette, was cut.
• the diamond is disposed with the crown upward and the table is in a horizontal position. It is in fact installed in an observation device according to the prior art, and it receives an incident light whose rays 18 have in this example an angle ⁇ of about 98 ° with respect to the horizontal, that is to say with respect to the plane of the table 2. This light passes through a bezel 4, being slightly deviated.
• the bezel has, relative to the horizontal, for example an angle ⁇ between 25 and 80 °, in particular from 33 to 37 °.
• the tip facets 10 and 12 have been cut so as to have, with respect to the horizontal, an angle ⁇ of between 25 and 52 °, advantageously between 36 and 41 °, preferably between 40 and 41 °.
• the angles are to be adapted according to the refractive indices typical of the different stones.
• the light beam 18, deflected by the bezel 4 is reflected on the tip facet 12 in the direction the opposing tip facet 10 where it is vertically reflected again, with projection through the crown table 2, i.e. perpendicular thereto.
• the intermediate location 16 of the point facet 12 has been chosen so that an incident ray which strikes it is also, after double reflection, projected through the table 2. This avoids a projection of the image. any portion of the tip facets through the crown facets and avoid some loss of gloss.
• the observable image in the observation device is clear, without optical deformation of the "arrow" type.
• the center of the diamond which is designated by the reference O in Figure 4.
• the location of the first reflection of the incident ray on the tip facet 12 is designated by the reference A.
• the projection of A on a horizontal plane passing through O gives a point A '.
• the location of the second reflection of the light beam on the opposite point facet 10 is designated by the reference B and the projection thereof on the horizontal plane passing through O is designated by the reference B '.
• the distance OA ' is greater than the distance OB', which means that the image displayed in the observation device is smaller than the reality.
• FIGS. 6 and 7 show an embodiment variant of ashlar according to the invention, in which the facets as well crown and breech received different shapes from those obtained in the stone according to Figures 1 and 2.
• the tip facets 9 to 12 extend here also between the colette 8 and an intermediate location between the Colette and the belt 7. They are arranged symmetrically with respect to the colette and extend on the same length, presenting each an elongated irregular shape of hexagon.
• the hatched image shows the image that could be observed by placing this stone, crown side upwards, in an observation device according to the previous state of the aforementioned technique.
• tip facets having other shapes and arranged not only cross but also for example in a rosette or so as to form a polygon around the acute colette.

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• Adornments (AREA)
• Polishing Bodies And Polishing Tools (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

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• 2005
  • 2005-05-25 BE BE2005/0259A patent/BE1016601A3/fr not_active IP Right Cessation
• 2006
  • 2006-05-19 CN CNA2006800178633A patent/CN101179960A/zh active Pending
  • 2006-05-19 EP EP06741306A patent/EP1895868B1/de not_active Not-in-force
  • 2006-05-19 WO PCT/BE2006/000055 patent/WO2006125281A1/fr active Application Filing
  • 2006-05-19 US US11/915,158 patent/US20080190139A1/en not_active Abandoned
  • 2006-05-19 JP JP2008512654A patent/JP2008541800A/ja active Pending
  • 2006-05-19 AT AT06741306T patent/ATE417522T1/de not_active IP Right Cessation
  • 2006-05-19 DE DE602006004341T patent/DE602006004341D1/de not_active Expired - Fee Related

Non-Patent Citations (1)

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