GB2303699A - A method and apparatus for detecting layers of synthetic diamond - Google Patents
A method and apparatus for detecting layers of synthetic diamond Download PDFInfo
- Publication number
- GB2303699A GB2303699A GB9515144A GB9515144A GB2303699A GB 2303699 A GB2303699 A GB 2303699A GB 9515144 A GB9515144 A GB 9515144A GB 9515144 A GB9515144 A GB 9515144A GB 2303699 A GB2303699 A GB 2303699A
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- GB
- United Kingdom
- Prior art keywords
- diamond
- radiation
- screen
- beams
- pattern
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- 239000010432 diamond Substances 0.000 title claims abstract description 162
- 229910003460 diamond Inorganic materials 0.000 title claims abstract description 158
- 238000000034 method Methods 0.000 title claims description 16
- 230000005855 radiation Effects 0.000 claims abstract description 90
- 238000012360 testing method Methods 0.000 claims abstract description 10
- 230000001678 irradiating effect Effects 0.000 claims description 15
- 238000010998 test method Methods 0.000 claims description 4
- 239000010410 layer Substances 0.000 description 17
- 239000000463 material Substances 0.000 description 17
- 238000005229 chemical vapour deposition Methods 0.000 description 13
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 239000010437 gem Substances 0.000 description 3
- 229910001751 gemstone Inorganic materials 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 239000004575 stone Substances 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- VZPPHXVFMVZRTE-UHFFFAOYSA-N [Kr]F Chemical compound [Kr]F VZPPHXVFMVZRTE-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229930014626 natural product Natural products 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/87—Investigating jewels
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Pathology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Medicinal Chemistry (AREA)
- Food Science & Technology (AREA)
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
In order to test whether a diamond 2 has had a layer of synthetic diamond deposited thereon, it is irradiated with ultraviolet radiation 4 so as to form a pattern of beams of refracted and reflected radiation, the pattern of reflected and refracted radiation being observed on a screen 5 behind the diamond 2. The screen 5 is a UV fluorescent screen and an observing means in the form of a CCD camera 7, is provided. The whole apparatus apart from the CCD camera may be enclosed within a light-tight box. The light source is provided by a laser 3 emitting UV radiation of a wavelength between 230-320 nm.
Description
EXAMINING A DIAMOND
Background to the Invention
The present invention relates to a method of and apparatus for testing whether a diamond has had a layer of synthetic diamond deposited thereon. This is of particular importance in testing whether the diamond comprises CvD diamond material and also in locating such material if present.
Synthetic diamond material may be deposited on an uncut or part processed natural diamond which is then worked, for example, into a round brilliant cut. Alternatively, the synthetic diamond material coating may be deposited onto a fully fashioned brilliant stone after working of the stone. The thickness of the synthetic diamond material layer may be very thin (it could be in the range from 5 Fm to 10 Fm) but the present invention may also be used to detect thicker layers.
The value of a diamond is in part dependent upon its weight. Accordingly, synthetic diamond material may be deposited onto natural gem diamonds, before or after cutting of the diamond, to increase the weight of the finished product.
However, the value of a diamond also resides in its qualities of authenticity and uniqueness and in the fact that it is an entirely natural product. Thus, a diamond that has not been enlarged by deposition of synthetic diamond material has a value over a diamond which has.
Over the years, a number of methods of synthesising diamond material have been developed. One of these methods is the chemical vapour deposition (CVD) technique, which is a low pressure technique involving deposition of synthetic diamond (referred to as CVD diamond material in this specification) onto a substrate from a gas. CvD is the most likely way in which synthetic diamond will be deposited on a diamond, although alternative techniques such as physical vapour deposition have been proposed. A diamond artificially enlarged by deposition of CvD or similar diamond material is referred to in this specification as a "CVD/natural diamond doublet11.
CVD diamond material may be deposited on a non-diamond or diamond substrate. In the latter case, the CVD diamond material can replicate the structure of the diamond substrate (referred to as "homoepitaxial growth"). The CVD/natural diamond doublet produced can be identical in appearance, density and other common physical properties to an entirely natural stone and there may be a problem in identifying such a CVD/natural diamond doublet.
A method of testing whether a diamond has had a layer of synthetic diamond deposited thereon is disclosed in
British Patent Application No. 9401354. 7. A plurality of parts of the diamond are irradiated with radiation substantially of wavelength substantially in the range 230nm to 320nm and the transmission of the irradiating radiation by the diamond is observed.
The invention of GB 9401354. 7 is based upon the observation that where different zones of a diamond show differences in their absorption of radiation substantially of wavelength substantially 230nm to 320nm, it may be concluded that the diamond in question has a layer of synthetic diamond deposited thereon. It is further observed that if all zones of a diamond strongly absorb radiation substantially of wavelength substantially 230nm to 320nm, the diamond may be classified as almost certainly a wholly natural diamond.
The intensity of radiation transmitted by the zones of the diamond may be investigated using an imaging apparatus or by placing the diamond in an integrating sphere. Preferably, an image of the diamond is formed against a dark or light background.
It is an object of the present invention to provide a method of and apparatus for testing whether a diamond has had a layer of synthetic diamond deposited thereon, in which relatively simple imaging apparatus is used and an expensive integrating sphere is not required.
It is desired that the apparatus should be simple and inexpensive and may be put into operation by a person with relatively little training. The method and apparatus should be capable of being operated reliably and consistently by a practised jeweller who has no training in laboratory gemological analysis.
The Invention
The present invention provides a method of testing whether a diamond has had a layer of synthetic diamond deposited thereon, comprising:
directing a beam of ultraviolet radiation towards a face of a diamond, so as to form a pattern of beams of radiation due to refraction and reflection of the irradiating radiation, and observing the pattern of such beams of radiation substantially of wavelength substantially in the range 230nm to 320nm
The present invention uses the same principles of absorption of certain wavelengths of ultra-violet radiation by certain types of diamond as used in GB 9401354. 7.
It is known from documents such as US 3947120 that where light is directed towards a cut gemstone, a pattern of spots of reflected and refracted radiation may be produced which is characteristic of each gemstone.
The present inventors have discovered that the different interaction of different types of diamond with ultraviolet radiation of the waveband in question can affect the pattern of spots obtained and help to identify superficial synthetic diamond layers.
In simple terms, substantial differences in the complexity and intensity of beams produced by different parts of the diamond (allowing for the shape of the diamond) suggest the presence of synthetic layers on the diamond.
In detail, the invention is based upon the observation that the majority of natural diamonds are classified as type IaA or IaAB and very strongly absorb ultraviolet radiation of wavelength shorter than approximately 320 nm, whereas a synthetic diamond layer will normally be of a type which strongly absorbs ultraviolet radiation of wavelength shorter than approximately 230 nm, in particular type II. Thus natural diamond is generally expected to give weak or unobservable reflected and refracted beams with radiation of wavelength shorter than 320 nm.
A synthetic diamond layer is generally expected to give a complex pattern of reflected and refracted beams. Any diamonds which give results suggesting the presence of a synthetic layer should be referred for further testing, as differences in the patterns of beams of reflected and refracted radiation may not be due to the presence of a synthetic diamond layer.
Preferably, substantially the whole of the presented face of the diamond is irradiated. This allows a complete pattern of beams to be formed and observed.
In principle, a single observation of the pattern of refracted and reflected beams of radiation could be sufficient to reveal the presence of a layer of synthetic diamond material. If, for example, a substantially symmetrical face of the diamond is exposed to the radiation and an asymmetric pattern of beams is obtained, the presence of layers of synthetic diamond may be suspected.
However, it is preferable to direct the beam of radiation to the diamond from a number of directions in succession and to compare the patterns obtained.
Interpretation of the results will be discussed further below.
It may be sufficient to test only a few faces (maybe only two) in order to detect a difference in the pattern of reflected and refracted beams. Preferably, however, a large number of faces are irradiated in succession.
The diamond may be irradiated with suitable radiation (as discussed below) by exposing it to radiation from a suitable source. The irradiating radiation may be focussed if necessary.
The beam of irradiating radiation may be of size less than the presented face of the diamond but is preferably greater in size.
Preferably, the pattern of reflected and refracted beams is observed by placing a screen a predetermined distance from the diamond so that the beams of reflected and refracted radiation impinge upon the screen, and detecting the pattern on the screen. Preferably an image of the pattern on the screen is formed.
The screen may be movable and angularly adjustable with respect to the diamond.
The screen is particularly preferably placed on the direction-of-irradiation side of the diamond, so that back-scattered reflected and refracted beams are observed. In this case, it is preferable that the irradiating radiation passes to the diamond through an aperture in the screen.
The screen may comprise an ultraviolet sensitive fluorescent screen for revealing the pattern of beams produced. In this case, the screen may be observed by eye through an observing means having a filter for cutting out hazardous irradiating radiation.
Alternatively, a camera may be used to observe the screen.
The radiation observed could comprise a narrow band of wavelengths lying substantially in the above mentioned range, a number of such narrow bands or it could be a relatively broad band. Optionally, it falls substantially in the range 230nm to 300nm, being preferably below 290nm. The radiation observed may comprise some radiation of wavelength falling outside the range 230 nm to 320 nm but such radiation is preferably of sufficiently low intensity to avoid confusing the beams observed at the wavelength of interest.
The radiation may be generated by a suitable laser, e. g a 248nm krypton fluoride excimer laser.
In order to observe radiation substantially of wavelength substantially 230 nm to 320 nm, the diamond may be irradiated only with such radiation (produced by a laser or by a wider band source having a filter).
Alternatively, the diamond may be irradiated with radiation of a broader range of wavelengths, wavelength selective means such as a filter being provided between the diamond and the screen or, imaging means to pass radiation of wavelength substantially 230 nm to 320 nm.
If the diamond is irradiated with radiation substantially of wavelength substantially 230 nm to 320 nm, wavelength selective means may also be provided to exclude radiation produced by fluorescence excited by the incident ultraviolet radiation. Normally, however, the intensity of fluorescence is not strong enough to require filtering.
When the irradiating radiation is incident on a zone of the diamond, it will generally be strongly absorbed or partially transmitted. The radiation transmitted by a zone of the diamond will be refracted inside the diamond and some transmitted radiation may be observed leaving the surface of the diamond. Thus, a pattern of beams of reflected and refracted radiation will be produced when a face of a diamond is irradiated.
The intensity of reflected beams from any given surface will depend in part upon the transmissivity of that surface and in part upon the angle of incidence of the radiation upon the surface. The intensity of refracted radiation beams will depend in part upon the transmissivity of the diamond material of a part observed and in part on its thickness.
Natural diamond usually has such a high absorption coefficient at the wavelengths in question that incident radiation is almost totally absorbed. CVD or other synthetic diamond material surface layers are commonly of a type that at least partially transmits the radiation, in particular type II diamond.
Thus, where a face of a diamond is irradiated normally and substantially no refracted beams are produced other than the reflection normal to the face, it may be concluded that the face is probably natural diamond.
Where a face is normally irradiated and a pattern of weak reflected and refracted beams is observed, the presence of a thin layer of synthetic diamond is indicated.
Where a face of a diamond is irradiated at a relatively large angle off the normal (referred to as "oblique irradiation"), and a relatively weak and simple pattern of reflected beams is produced, it may be concluded that the face irradiated comprises natural diamond. If, however, a pattern of relatively strong and complex reflected and refracted beams is observed, the presence of synthetic diamond material is suggested.
Any suggestion of synthetic diamond material should be followed up with further testing, as the reflected and refracted beams may be due to natural diamond of a rare type.
If a diamond is irradiated on a face which is substantially symmetrical, and a pattern which is grossly unsymmetrical (for example, light on one side, dark on the other) is produced, it may be concluded that the sides of the face of the diamond presented are of different composition.
Because of the complex pattern of light paths within a brilliant-cut diamond, the two parts of a CVD/natural diamond doublet may not be immediately apparent. It may be necessary to manipulate a CVD/natural diamond doublet while it is being viewed, in order to clearly see the two parts of the diamond.
In order to assist in the interpretation of the patterns of reflected and refracted beams produced when a diamond is irradiated with the first mentioned radiation, the diamond may be irradiated with radiation which is substantially transmitted by all types of diamond, such as visible radiation, so that a reference pattern may be formed. This pattern may then be compared to a pattern obtained using the first mentioned radiation, preferably with the diamond in the same configuration.
The reference pattern is expected to show relatively strong and complex patterns of reflected and refracted radiation for all types of diamond.
The present invention further provides apparatus for testing whether a diamond has had a layer of synthetic diamond deposited thereon, comprising means for irradiating the diamond with ultraviolet radiation, and a screen mounted a predetermined distance from the diamond so that the screen intercepts a pattern of beams of reflected and refracted radiation produced when a diamond is irradiated, andmeans for allowing the pattern of beams of radiation substantially of wavelength substantially in the range 230nm to 320nm on the screen to be observed.
The apparatus according to the invention could be automated to automatically interpret and analyse images or readings produced. However, this is not preferred, as a simple system in which the images are interpreted by the operator is practicable and cheaper.
The invention will be further described by way of example only, with reference to the accompanying drawings, in which:
Brief Description of the Drawings
Figure 1 is a schematic illustration of apparatus according to the invention; and
Figures 2a - 2f are schematic illustrations of patterns of reflected and refracted beams produced according to the present invention when various diamonds are irradiated with ultraviolet or visible radiation.
Detailed Description of the Drawings
In the apparatus shown schematically as 1 in figure 1, a diamond 2 is irradiated with radiation of wavelength substantially in the range 230-320nm by a laser 3. The laser beam 4 is directed through a screen 5, through an aperture 6 provided in the middle thereof. When the beam of radiation 4 is incident upon the diamond 2, a pattern of beams of reflected and refracted radiation may be produced. The pattern produced in the back-scattered direction is studied in the embodiment shown in figure 1. The screen 5 is movable and angularly adjustable. The pattern is studied by arranging the screen 5 at a distance from the diamond 2 such that substantially all the beams of reflected and refracted radiation are intercepted by the screen.
Typically, for a screen of size 100 mm x 100 mm, the distance between the diamond and the screen is circa 60 mm.
An observing means 7 is provided for observing the pattern of reflected and refracted beams formed on the screen 5.
The screen 5 is a UV fluorescent screen, which generates spots of visible light where ultraviolet radiation of wavelength 230-320nm is incident upon it. The observing means 7 may comprise a suitable optical device with a filter for filtering out radiation of ultraviolet wavelengths, which can be dangerous to the eye.
The whole apparatus 1, except for the observing means 7 may be enclosed in a light-tight box, for excluding external radiation which may confuse the pattern on the screen and for containing the dangerous W radiation.
The observing means 7 may be mounted at a suitable position within the walls of the light-tight box so that an observer can see the pattern on the screen 5.
In order to provide a reference pattern, a laser 8 producing light of a visible wavelength is provided. A beam splitter 9 is provided in the path of beam 4 so that the visible radiation from laser 8 may be directed down the path of the irradiating radiation 4 from laser 3. Preferably, lasers 3 and 8 are used in alternation so that the different patterns produced by the different types of radiation may be compared.
In figures 2a to 2f, the results of irradiation of a diamond according to the invention are shown.
Three cases were studied: a. A diamond which is a CVD/natural diamond doublet, with the synthetic part on the culet of the diamond, b. A CVD/natural diamond doublet in which the synthetic diamond is formed on the table of the diamond, c. A completely natural diamond
In each case, the diamond is a cut diamond having a brilliant cut, being the type of cut which will be most frequently encountered.
The diamond is irradiated using the three steps: 1. irradiation of the table in a normal direction using ultraviolet radiation of wavelength substantially in the range 230-320nm, 2. normal irradiation of the table using visible radiation, and 3. irradiation of the culet using ultraviolet radiation substantially of wavelength falling in the range substantially 230-320nm.
The above-mentioned three types of diamond can be distinguished by the different patterns of reflected and refracted radiation that they produce.
In figures 2a - 2f, spots of high intensity are shown as a solid black dot, spots of medium intensity are shown as short complete lines and spots of low intensity are shown as short, dotted lines.
In figures 2a - 2c, the results of steps 1 and 2 are shown on a single screen for comparison, though in practice they would be separate.
Figure 2a shows the results of steps 1 and 2 with diamond (a).
The pattern on the screen in step 1 is observed to comprise a single high intensity spot 10 produced by normal reflection of the irradiating radiation.
In step 2, a complex relatively intense pattern of spots 11 is observed.
Figure 2b shows the results of steps 1 and 2 with diamond (b). In step 1, a pattern of reflected and refracted beams 12 of relatively low intensity is observed. In step 2, a pattern of reflected and refracted beams of relatively high intensity is produced. The patterns are different, as the refractive index of diamond at the ultraviolet wavelengths observed is different to the refractive index of visible radiation.
Figure 2c shows the results of steps 1 and 2 with diamond (c). In step 1 a single relatively high intensity spot 14 is produced by normally reflected radiation only. In step 2, a relatively intense and complex pattern of reflected and refracted beams 15 is produced. The patterns observed in figure 2c are similar to those shown in figure 2a.
Figure 2d shows the results of step 3 with the diamond (a). A relatively complex pattern of strong reflected and refracted beams 17 is produced, together with a strong beam 16 due to radiation reflected normally from the culet (assuming that there is a culet facet).
Figure 2e shows the results of step 3 with diamond (b).
A relatively weak simple pattern of reflected beams 18 is produced due to reflection off the cut surfaces around the culet.
Figure 2f shows the results of step 3 with diamond (c).
A simple pattern of relatively weak reflected beams 19 is produced.
In the apparatus shown in figure 1, the ultraviolet laser may comprise a 248nm krypton fluoride excimer laser from Potomac lasers. The laser 8 may comprise a 635 nm'laser diode or 633nm HeNe laser from Vector technology/Melles Griot. The beam splitter 9 is manufactured by Spindler and Hoyer and the ultraviolet sensitive fluorescent screen is supplied by Levy-Hill
Ltd. If a camera is used to observe the screen 5, it may be a CCD camera coupled to a computer for analysing the spot pattern produced.
Claims (15)
1. A method of testing whether a diamond has had a layer of synthetic diamond deposited thereon, comprising:
directing a beam of ultraviolet radiation towards a face of the diamond, so as to form a pattern of beams of radiation due to refraction and reflection of the irradiating radiation, and
observing the pattern of beams of radiation substantially of wavelength substantially in the range 230nm to 320nm.
2. A method according to claim 1 further comprising directing a beam of ultraviolet radiation to a second face of the diamond and observing the pattern of beams of radiation substantially of wavelengths substantially in the range 230-320 nm produced by the second surface and comparing the pattern of beams of the first-mentioned face of the diamond and the second face of the diamond.
3. A method according to claim 1 or 2, wherein a large number of faces of the diamond are irradiated in succession.
4. A method according to any of claims 1 to 3, wherein the pattern of reflected and refracted beams is observed by placing a screen a predetermined distance from the diamond so that the beams of refracted and reflected radiation impinge upon the screen and detecting the pattern of beams on the screen.
5. A method according to claim 4, wherein an image of the screen is formed.
6. A method according to claim 4 or 5, wherein the screen is placed on the di rection-of-irradiati on side of the diamond, so that back-scattered reflected and refracted beams are observed.
7. A method according to claim 4, 5 or 6, wherein the screen comprises an ultraviolet sensitive fluorescent screen.
8. A method according to any preceding claim, further comprising forming a reference image by irradiating the face of the diamond with radiation which is substantially transmitted by all types of diamond.
9. Apparatus for testing whether a diamond has had a layer of synthetic diamond deposited thereon, comprising:
means for irradiating the diamond with ultraviolet radiation;
a screen mounted at a predetermined distance from the diamond so that the screen intercepts a pattern of beams of reflected and refracted radiation produced when a diamond is irradiated, and
means for allowing the pattern of beams of radiation substantially of wavelength substantially in the range 230nm to 320nm on the screen to be observed.
10. Apparatus according to claim 9, wherein the screen comprises an ultraviolet fluorescent screen.
11. Apparatus according to claim 9 or 10, wherein the irradiating means comprises a laser.
12. Apparatus according to any of claims 9 to 11, further comprising means for irradiating the diamond with radiation which is substantially transmitted by all types of diamond.
13. Apparatus according to any of claims 9 to 12, wherein the screen is placed on the direction-of-irradiation side of the diamond for intercepting back-scattered reflected and refracted beams from the diamond.
14. A method of testing whether a diamond has had a layer of synthetic diamond deposited thereon, substantially as herein described with reference to the accompanying drawings.
15. Apparatus for testing whether a diamond has had a layer of synthetic diamond deposited thereon, substantially as herein described with reference to the accompanying drawings.
Priority Applications (14)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9515144A GB2303699A (en) | 1995-07-24 | 1995-07-24 | A method and apparatus for detecting layers of synthetic diamond |
CA002227620A CA2227620A1 (en) | 1995-07-24 | 1996-07-22 | Examining a diamond |
EP96925015A EP0840891A1 (en) | 1995-07-24 | 1996-07-22 | Examining a diamond |
KR1019980700561A KR19990035900A (en) | 1995-07-24 | 1996-07-22 | Inspection of diamonds |
JP9506453A JPH11509630A (en) | 1995-07-24 | 1996-07-22 | Inspection of diamond |
AU65272/96A AU711507B2 (en) | 1995-07-24 | 1996-07-22 | Examining a diamond |
CN96196981A CN1196121A (en) | 1995-07-24 | 1996-07-22 | Examining diamond |
PCT/GB1996/001752 WO1997004303A1 (en) | 1995-07-24 | 1996-07-22 | Examining a diamond |
GB9800373A GB2317693B (en) | 1995-07-24 | 1996-07-22 | Examining a diamond |
ZA966246A ZA966246B (en) | 1995-07-24 | 1996-07-23 | Examining a diamond |
IL11892196A IL118921A0 (en) | 1995-07-24 | 1996-07-23 | Examining a diamond |
TW088202463U TW433464U (en) | 1995-07-24 | 1996-07-24 | Examining a diamond |
HK98111054A HK1014446A1 (en) | 1995-07-24 | 1998-09-29 | Examining a diamond |
US09/766,338 US6331708B2 (en) | 1995-07-24 | 2001-01-19 | Examining a diamond |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9515144A GB2303699A (en) | 1995-07-24 | 1995-07-24 | A method and apparatus for detecting layers of synthetic diamond |
Publications (2)
Publication Number | Publication Date |
---|---|
GB9515144D0 GB9515144D0 (en) | 1995-09-20 |
GB2303699A true GB2303699A (en) | 1997-02-26 |
Family
ID=10778161
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9515144A Withdrawn GB2303699A (en) | 1995-07-24 | 1995-07-24 | A method and apparatus for detecting layers of synthetic diamond |
Country Status (12)
Country | Link |
---|---|
EP (1) | EP0840891A1 (en) |
JP (1) | JPH11509630A (en) |
KR (1) | KR19990035900A (en) |
CN (1) | CN1196121A (en) |
AU (1) | AU711507B2 (en) |
CA (1) | CA2227620A1 (en) |
GB (1) | GB2303699A (en) |
HK (1) | HK1014446A1 (en) |
IL (1) | IL118921A0 (en) |
TW (1) | TW433464U (en) |
WO (1) | WO1997004303A1 (en) |
ZA (1) | ZA966246B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6377340B1 (en) * | 1999-10-29 | 2002-04-23 | General Electric Company | Method of detection of natural diamonds that have been processed at high pressure and high temperatures |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7102742B2 (en) * | 2004-01-12 | 2006-09-05 | Gemological Institute Of America, Inc. | Fluorescence measuring device for gemstones |
KR100904637B1 (en) | 2007-07-30 | 2009-06-25 | 한양대학교 산학협력단 | Discrimination method of diamonds |
AU2011259699A1 (en) * | 2010-05-25 | 2012-05-17 | Ninomiya Jewelry, Co.,Ltd. | Device for measuring properties of scatterers, color measuring device for scattered light of gemstones, device for measuring brightness of gemstones, and device for measuring luminescence distribution |
JP5033266B1 (en) * | 2010-11-15 | 2012-09-26 | 二宮宝石株式会社 | Luminescent light emission distribution measuring device, scatterer physical property measuring device, and gem scattered light color measuring device |
AT514332B1 (en) | 2013-08-27 | 2014-12-15 | Swarovski D Kg | Arrangement for analyzing a light pattern caused by refraction and reflection on a gemstone |
JP6041909B2 (en) * | 2015-01-15 | 2016-12-14 | 株式会社ダイアモンドグレーディングラボラトリー | Jewelry observation equipment |
US9678018B2 (en) | 2015-03-30 | 2017-06-13 | Gemological Institute Of America Inc. (Gia) | Apparatus and method for assessing optical quality of gemstones |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0071462A1 (en) * | 1981-07-27 | 1983-02-09 | Lce, Ltd. | Method and apparatus for analyzing gems |
GB2215041A (en) * | 1988-01-29 | 1989-09-13 | Argyle Diamond Sales | Sorting and/or confirming the identity of gems |
GB2267147A (en) * | 1992-05-19 | 1993-11-24 | Gersan Ets | Classifying objects, E.G. Diamonds, by radiation transmission |
GB2286251A (en) * | 1994-01-25 | 1995-08-09 | Gersan Ets | Examining a diamond for synthetic diamond |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5015597Y1 (en) * | 1969-08-24 | 1975-05-15 | ||
IL43465A (en) * | 1973-10-23 | 1976-12-31 | Yeda Res & Dev | Gem identification |
GB2275788B (en) * | 1993-03-05 | 1996-07-31 | Gersan Ets | Distinguishing natural from synthetic diamond |
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1995
- 1995-07-24 GB GB9515144A patent/GB2303699A/en not_active Withdrawn
-
1996
- 1996-07-22 WO PCT/GB1996/001752 patent/WO1997004303A1/en not_active Application Discontinuation
- 1996-07-22 CN CN96196981A patent/CN1196121A/en active Pending
- 1996-07-22 AU AU65272/96A patent/AU711507B2/en not_active Ceased
- 1996-07-22 EP EP96925015A patent/EP0840891A1/en not_active Ceased
- 1996-07-22 CA CA002227620A patent/CA2227620A1/en not_active Abandoned
- 1996-07-22 JP JP9506453A patent/JPH11509630A/en active Pending
- 1996-07-22 KR KR1019980700561A patent/KR19990035900A/en not_active Application Discontinuation
- 1996-07-23 IL IL11892196A patent/IL118921A0/en unknown
- 1996-07-23 ZA ZA966246A patent/ZA966246B/en unknown
- 1996-07-24 TW TW088202463U patent/TW433464U/en not_active IP Right Cessation
-
1998
- 1998-09-29 HK HK98111054A patent/HK1014446A1/en not_active IP Right Cessation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0071462A1 (en) * | 1981-07-27 | 1983-02-09 | Lce, Ltd. | Method and apparatus for analyzing gems |
GB2215041A (en) * | 1988-01-29 | 1989-09-13 | Argyle Diamond Sales | Sorting and/or confirming the identity of gems |
GB2267147A (en) * | 1992-05-19 | 1993-11-24 | Gersan Ets | Classifying objects, E.G. Diamonds, by radiation transmission |
GB2286251A (en) * | 1994-01-25 | 1995-08-09 | Gersan Ets | Examining a diamond for synthetic diamond |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6377340B1 (en) * | 1999-10-29 | 2002-04-23 | General Electric Company | Method of detection of natural diamonds that have been processed at high pressure and high temperatures |
Also Published As
Publication number | Publication date |
---|---|
WO1997004303A1 (en) | 1997-02-06 |
GB9515144D0 (en) | 1995-09-20 |
EP0840891A1 (en) | 1998-05-13 |
TW433464U (en) | 2001-05-01 |
AU6527296A (en) | 1997-02-18 |
AU711507B2 (en) | 1999-10-14 |
ZA966246B (en) | 1998-10-23 |
CA2227620A1 (en) | 1997-02-06 |
HK1014446A1 (en) | 1999-09-30 |
JPH11509630A (en) | 1999-08-24 |
CN1196121A (en) | 1998-10-14 |
IL118921A0 (en) | 1996-10-31 |
KR19990035900A (en) | 1999-05-25 |
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