Gemstone and jewelry inspection device

Abstract

Ensuring the same gemstones are returned by a jewelry service provider has become critical as synthetic diamonds have become prolific. Natural, synthetic and imitation gemstones can respond differently to excitation by specific frequencies or wavelengths. Cost-effective light-emitting diodes (LEDs) and narrow bandwidth wavelength laser diodes can induce unique or characteristic fluorescence and phosphorescence reactions of these materials. By illuminating gemstones in a darkened environment these reactions can be observed with appropriate colour filters visually or photographed. Photographs of these optical responses can be stored and referenced for future identification and verification, as evidence that the same gems have been returned to owners. This device also enables minimally trained people to discriminate diamonds that may be synthetic that may need to be referred to more expensive and accurate assessment where the owner believed the diamonds to be natural, whether loose or set in jewelry.

Description

GEMSTONE AND JEWELRY INSPECTION DEVICEBACKGROUND OF THE INVENTION

[0001] For over a century, it has been recognized that many natural gemstones, synthetic gemstones, and imitation gemstones can exhibit luminescence, including fluorescence and phosphorescence. These phenomena involve the emission of visible light when the material is exposed to specific excitation radiation. Traditionally, such excitation has been achieved using ultraviolet (UV) light with wavelengths below 400 nanometres. However, it is now understood that visible and infrared light can also induce luminescent responses, broadening the range of potential excitation sources.

[0002] By applying precise, narrow-band illumination at specific wavelengths, luminescence can reveal unique or characteristic spectral distributions. These emissions, perceived as distinct colors, are influenced by the gemstone's composition and structure. For instance, fluorescence or phosphorescence may serve as evidence of a gemstone's natural origin, synthetic nature, or imitation status. In some cases, the absence of fluorescence can also provide crucial insights into a stone’s identity and provenance.

[0003] Luminescent behaviors often arise from specific properties within a gemstone’s structure:Crystallographic Defects: Lattice imperfections, like nitrogen-associated vacancies in diamond, generate distinct fluorescence patterns. These defects, such as NV centers or N3 producing blue fluorescence and H3 and H4 defect sites, producing green or greenish-yellow fluorescence in natural diamonds, resulting in identifiable luminescent emissions under specific excitations.Allochromatic Components: Foreign trace elements, such as chromium -3 in rubies, red spinel, and alexandrite, or manganese in kunzite and garnet, contribute to fluorescence.Idiochromatic Fluorophores: Intrinsic elements, such as uranium in certain minerals, naturally fluoresce due to their essential role in the material’s composition.

[0004] The rise of synthetic diamonds since 2014 has intensified the need for reliable identification methods. Synthetic diamonds, often significantly cheaper than natural ones, are visually indistinguishable from natural diamonds using traditional tools like jeweler’s loupes. This poses risks of fraud, misrepresentation, and challenges during jewelry repair or appraisal. For example, customers may unknowingly submit jewelry containing synthetic or imitation gemstones, leading to potential disputes about stone replacement during servicing.

[0005] Existing instruments for identifying synthetic diamonds are often costly, complex, and sometimes require expertise, making them unsuitable for routine use by many people in the jewelry industry. Cheaper alternatives also depend heavily on the operator’s experience and may lack reliability. Moreover, many devices only differentiate between Type I and Type II diamonds, the latter being nitrogen-pure. Approximately 97-99% of natural diamonds are Type I and many display characteristic blue fluorescence due to N3 centers as well as H3 and H4 defect sites, producing green or greenish-yellow fluorescence. Conversely, almost all of the most common synthetic colorless diamonds are currently Type II and do not exhibit such fluorescence, providing a potential diagnostic clue.

[0006] The current invention addresses these challenges with a simple, cost-effective device that jewelry industry personnel can use with minimal training. This device allowsquick and preliminary jewelry and gemstone assessments, identifying fluorescence responses and facilitating referrals for more sophisticated testing when required.

[0007] Key features include:Visible and Smartphone-Compatible Observations: The device enables fluorescence inspection and photography using smartphones. These images can serve as records for identifying gemstones and preventing fraudulent claims.Ease of Use for Multi-Stone Jewelry: For pieces with multiple diamonds, characteristic fluorescence from even a subset of stones can provide strong evidence of natural or synthetic origin, as well as note the visual effects of imitation stones.Customer Engagement and Record-Keeping: Photos of gemstones’ fluorescence can be shared electronically with customers during submission, aiding in future identification and fostering trust. This also allows the capture of customer contact information that may be valuable for a business.

[0008] This tool is not a substitute for advanced techniques but serves as a practical first line of analysis for identifying gemstones in jewelry settings. It provides an accessible solution for jewelry retailers, reducing reliance on expensive equipment and expert gemologists while protecting against fraudulent claims and ensuring confidence in gemstone authenticity.SUMMARY OF THE INVENTION

[0009] The present invention relates to a compact internally-darkened closed container designed as a viewing box for examining gemstones or mounted jewelry pieces. The device features an observation and photography aperture and is equipped with internal illumination sources capable of emitting selected narrow ranges of excitation wavelengths, predominantly in the near visible and visual spectrum. These excitationsources, which use specific and relatively safe wavelengths, induce characteristic fluorescence or phosphorescence in gemstones, enabling visual observation and photographic documentation. The observed luminescence behaviors, such as color and spectral emission distributions, can be correlated with known properties of specific gem materials, providing a means of identification, recognition, and ownership assurance.

[0010] This invention allows users to differentiate natural gemstones, such as diamonds, from synthetic or imitation counterparts, particularly in larger quantities of smaller sized diamonds (melee) and among various non-diamond imitations. It achieves this by utilizing one or more visible, or near-visible light and ultraviolet (UV) wavelengths to elicit and observe fluorescence and phosphorescence responses in gemstones. The device’s inexpensive design enables even untrained users, such as salespeople, pawn brokers, and jewelry repair personnel, to quickly and reliably enable a record of and assess the authenticity and type of gemstones without requiring advanced gemological expertise.

[0011] Key features of the invention include:Ease of Use: The device is simple to operate, requiring minimal training to produce clear results to identify a piece of jewelry or loose diamonds to be subsequentially returned. Users and customers can easily identify whether gemstones exhibit or lack fluorescence properties further enabling the likelihood that the gems are natural diamonds or other materials.Low Cost: The device’s components are inexpensive, making it suitable for mass production and widespread adoption across the jewelry industry.Versatility: The invention is effective for a variety of gemstones, aiding in the identification of natural, synthetic, and imitation stones. It is particularly useful forverifying the authenticity of diamonds and ensuring that gemstones in serviced or repaired jewelry pieces remain unchanged.BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 shows a plan view of an embodiment.Fig. 2 shows a side view of an embodiment.Fig. 3 shows a front view of an embodiment.Fig. 4 shows a cutaway view of the inside of an embodiment with the base removed showing the power supply.Fig. 5 shows a cut away of the device in use.DETAILED DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 plan view shows the viewing aperture 101 with an inner circle to rest barrier filters 103. 102 shows, in this embodiment, four button switches to turn on one of each of the four illumination sources. 103 represents one or more various filters used to screen out the visible illumination from the appropriate light source. Each of these filters could be framed in the same color as the appropriate light button. 104 shows 4 rests to position a smartphone to view, take photos and if required send electronically. 105 is a small handle to enable opening of the door to enable placement of items to be inspected. 106 shows a USB or power supply port.

[0013] Fig. 2 is an internal side elevation of the device, illustrating the light-sealed enclosure, matte-black internal surfaces. 201 shows the light sealing access door. 202 shows the aforementioned power supply port. 203 shows hinge. 204 shows the safety switch to turn off potentially dangerous illumination sources.

[0014] Fig. 3 shows the door 301 and handle 303. 302 is covering an optional embodiment of a lower section containing a power supply and rechargeable battery to power the sources of illumination.

[0015] Fig. 4 shows a cutaway 400 of the interior of the current embodiment with the non-fluorescent base or floor removed to reveal the aforementioned 401 power supply to the rechargeable battery 402.

[0016] Fig. 5 shows 501 the smartphone and supports. 502 shows a barrier filter. 503 shows an embodiment with one illuminator and an illumination zone. 504 shows a jewelry object to be examined. 505 shows a non-fluorescent jewelry mount. 506 shows the aforementioned safety switch to turn off irradiation when the door is opened.DETAILED DESCRIPTION OF THE INVENTION

[0017] The device enables observation and photographic recording of the luminescence of gemstones under excitation illumination. It is designed to examine materials such as rubies, pink sapphires, diamonds, alexandrites, red spinels, various types of non-ferruginous garnets, and other natural or synthetic lapidary materials. These gemstones can be observed in their loose, mounted, polished, or rough forms. Distinctive luminescence emissions, including fluorescence and / or phosphorescence, serve as permanent evidence for identifying specific gem materials. This capability is particularly beneficial for determining whether diamonds are of natural (mined) origin, treated and enhanced or of synthetic (man-made) origin.

[0018] Diamonds can display varying fluorescence emissions depending on the wavelength of excitation. Long-wave ultraviolet (LWIIV) light, approximately 300-405 nm, excites the visibly blue-fluorescing N3 defect site, characterized by a unique zero phonon line (ZPL) at 415 nm and associated vibronic features extending further into the visible spectrum. Additionally, bright-blue excitation at 450 nm specificallystimulates the H3 and H4 defect sites, producing green or greenish-yellow fluorescence, while minimizing interference from the blue-emitting N3 site. This selective stimulation prevents overlapping emissions, ensuring clear and accurate observations.

[0019] The device can, for example, also utilize green 532 nm visible but narrow wavelength light sources to induce deep-red fluorescence in certain natural diamonds. Although this red fluorescence may be indistinguishable from the intense green excitation under normal viewing conditions, it becomes detectable when a red barrier filter, such as selenium-red glass, is employed. This filter blocks the green excitation and isolates the red fluorescence, employing a technique analogous to the Chelsea filter method widely used in gemology for identifying chromic-containing gemstones. There are various colored filters available to enable the blocking of other specific visible wavelengths that can be employed with other narrow wavelength diode laser or LED sources.

[0020] Furthermore, other diamond defect sites may exhibit characteristic fluorescence or phosphorescence when exposed to a range of excitation wavelengths, from ultraviolet to visible and into the infrared spectrum. Key excitation wavelengths for natural diamond fluorescence include those produced by diode lasers or LEDs, centered at approximately 385 nm, 405 nm, 450 nm, and 532 nm. Additional wavelengths may be employed to stimulate less commonly encountered luminescent centers.

[0021] In the case of natural diamond detection from synthetic diamond: Applying a first excitation centers on the minimally-visible LWUV 385 nm, which minimizes visual interference from the otherwise overwhelming excitation illumination intensity on the generated blue fluorescence. The site that is stimulated is particularly the N3 defect indiamonds at its unique 415 nm ZPL fluorescent peak plus its slightly longer (blue visible) broader vibronic-phonon band. Secondly, an alternative illuminator centered on ("royal blue") 450 nm, selectively excites the diamond H3 and H4 centers to fluoresce green to green-yellow as well as the 520 nm fluorescence emission band of possibly uncertain origin, and without exciting the N3 fluorescence, which could otherwise be confusing. All of these fluorescent diamond sites are unique to only natural, mined diamonds of the Type I category which constitutes up to at least about 95% of all natural mined diamonds. These fluorescent sites are not presently known to occur in synthetic HPHT or CVD diamonds, the latter especially being almost exclusively Type IIA, which is generally very low in aggregated nitrogen-defect sites and is not-fluorescent or not-identically-fluorescent to these particular excitations.

[0022] Other gemstones, such as rubies, pink sapphires, alexandrites, and red spinels, exhibit crimson fluorescence under LWIIV due to their trace chromic content. Nearultraviolet stimulation (e.g., 385-405 nm) and visible wavelengths, such as 450 nm (royal blue) and 532 nm (green), are also effective in eliciting strong fluorescence. A variety of other gem materials, including pearls, non-ferruginous garnets, spodumenes (e.g., kunzites), natural opals, ambers, and beryl’s (notably synthetic emeralds), can be observed contributing to identification using the device. These materials often exhibit unique fluorescence signatures in response to specific excitation wavelengths, aiding in their identification and authentication.

[0023] Notably, many gem materials respond to narrow wavelength ranges of excitation, enhancing the precision and utility of the device for gem identification. By enabling visual observation, photographic and video documentation of these luminescence characteristics, the device provides a reliable and versatile tool for gemological analysis and authentication across a wide range of gemstones.

Claims

CLAIMS1. A gemstone inspection device, comprising:o An internally-darkened viewing box designed for examining gemstones or mounted jewelry pieces;o Internal illumination sources capable of emitting narrow-bandwidth excitation wavelengths, predominantly within ultraviolet, visible, and infrared ranges;o An observation and photography aperture configured to allow visual inspection and photographic recording of gemstone luminescence.

2. The device of claim 1, wherein the illumination sources include light-emitting diodes (LEDs) and / or laser diodes emitting specific wavelengths, including but not limited to 385 nm, 405 nm, 450 nm, and 532 nm.

3. The device of claim 1 , further comprising:o Interchangeable color filters designed to selectively block excitation wavelengths, enabling enhanced observation of fluorescence and / or phosphorescence emissions.

4. The device of claim 1, configured to analyse luminescence responses in gemstones to differentiate natural gemstones from synthetic or imitation counterparts.

5. The device of claim 1, wherein the luminescence responses are recorded photographically using integrated or external imaging devices, including smartphone cameras.

6. The device of claim 1 , designed for use with a variety of gemstone types, including diamonds, rubies, pink sapphires, alexandrites, red spinels, garnets, opals, and synthetic materials.

7. The device of claim 1, wherein excitation illumination highlights specific defect sites in diamonds, including N3, H3, and H4 centres, to produce characteristic fluorescence emissions.

8. The device of claim 1 , further configured to utilize a red barrier filter or equivalent optical filter to isolate deep-red fluorescence emissions from diamonds under green excitation.

9. The device of claim 1 , designed to operate with minimal training, enabling nonspecialist users such as jewelry store personnel to perform gemstone assessments.

10. The device of claim 1 , wherein photographic records of gemstone luminescence are stored digitally for future reference, aiding in identification, verification, and ownership assurance.

11. The device of claim 1 , configured to analyse gemstones in multiple forms, including loose stones, mounted jewelry, polished, or rough items.

12. A method for gemstone identification, comprising:o Placing a gemstone in a darkened environment;o Illuminating the gemstone with narrow-bandwidth excitation wavelengths using light-emitting diodes or laser diodes;o Observing and recording luminescence emissions visually or photographically;o Comparing the luminescence characteristics to known gemstone fluorescence and phosphorescence behaviours for identification and authentication purposes.

13. The method of claim 12, wherein the luminescence emissions are used to determine whether a gemstone is natural, synthetic, or an imitation.

14. The method of claim 12, further comprising sharing photographic records with customers for verification and ownership assurance such as during jewelry repair or appraisal.

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