Our Testing Laboratory

Visual inspection of jewelry, diamonds, and bullion provides valuable insights and complements scientific testing. While it may not offer the precision of laboratory methods, it still holds several important benefits:

Initial Assessment: Visual inspection is often the first step in evaluating a piece. It allows us to quickly assess the overall condition, craftsmanship, and potential value before proceeding with more formal testing.

Identifying Obvious Defects: A trained eye can detect surface flaws, damage, or wear that may affect the piece’s value. Cracks, chips, or tarnishing can be spotted easily, providing an opportunity for further scrutiny.

Artistic and Aesthetic Evaluation: Jewelry and gemstones are not only valued for their material content but also for their design, cut, and craftsmanship. A visual inspection allows for appreciation of the artistic aspects that might not be captured through scientific testing.

Detecting Fake or Misrepresented Items: We can often spot common signs of counterfeiting or misrepresentation, such as fake hallmarks, altered settings, or inconsistent markings, which might warrant further verification.

Quick Verification for Low-Risk Transactions: In cases where a transaction is less high-stakes or the value of the item isn’t extraordinary, visual inspection can provide enough assurance without the need for lab tests.

Recognizing Wear and Maintenance Needs: Visual inspection helps determine whether a piece requires cleaning, repair, or adjustment, which can influence its resale value or desirability.

Immediate Feedback: Visual inspection offers instant feedback, allowing for quick decision-making.

In summary, visual inspection provides an accessible, immediate way to evaluate jewelry, diamonds, and bullion, offering key insights into aesthetic, condition, and authenticity that can inform whether further testing or validation is needed.

Magnetic testing of jewelry and bullion offers a simple, non-destructive method to assess the authenticity of metals. While not a comprehensive verification technique, it provides several key benefits:

Detecting Non-Precious Metals: Precious metals like gold, silver, and platinum are non-magnetic, so if a piece of jewelry or bullion is attracted to a magnet, it may contain non-precious metals like iron, nickel, or cobalt, which are magnetic. This quick test can help identify fake or misrepresented items.

Immediate: Magnetic testing provides an instant result. It’s an effective method for initial screening, especially in situations where lab tests may not be justified.

Non-Destructive: Magnetic testing doesn’t damage or alter the item in any way, making it ideal for use on delicate or high-value pieces where preservation of the item is essential.

Preliminary Fraud Detection: In cases where bullion or jewelry has been plated with a precious metal but filled with a base metal core, magnetic testing can help expose this by revealing magnetic properties beneath the surface. This is sometimes useful for detecting counterfeit bullion bars or coins.

Complementary to Other Tests: While magnetic testing alone may not conclusively determine authenticity, it can be used alongside other testing methods like visual inspection, density analysis, and scientific testing to build a more comprehensive understanding of the item’s composition.

Quick Verification for High-Volume Transactions: In situations like buying or selling large quantities of bullion or jewelry, magnetic testing can quickly weed out suspect items, allowing for faster sorting before more detailed evaluation.

In summary, magnetic testing is a practical, non-invasive tool that helps quickly identify fraudulent or inauthentic pieces, especially when used in combination with other testing methods. It serves as an efficient first-line defense in ensuring the integrity of precious metals in jewelry and bullion.

Electrical conductivity testing of jewelry and bullion offers a precise and reliable method for assessing the composition and authenticity of precious metals. This technique measures how well a material conducts electricity, which can reveal important information about its metal content. Here are the key benefits of this testing method:

Accurate Metal Identification: Different metals have distinct conductivity levels. Precious metals like gold, silver, and copper are excellent conductors, while others, such as tungsten or nickel (commonly used in counterfeits), are less conductive. Electrical conductivity testing helps verify if the metal matches the expected conductivity for authentic gold, silver, or other precious metals.

Non-Destructive: Like magnetic testing, electrical conductivity testing is non-invasive and doesn’t damage the item. It allows for precise analysis without altering or compromising the appearance or integrity of the jewelry or bullion.

Detecting Counterfeits: Counterfeit items often use metals with different conductivity properties from the genuine ones. Electrical conductivity testing can easily detect these differences, helping to identify fake items that might otherwise pass visual inspection or basic magnetic testing.

Verifying Purity: In bullion, especially with coins and bars, electrical conductivity testing can help verify the purity of the metal. For example, pure gold (24k) has higher conductivity than lower karat gold alloys or gold-plated items, offering a reliable method to confirm whether an item is pure or alloyed.

Testing Layered or Plated Metals: Electrical conductivity testing can be especially effective in detecting whether a piece is solid or merely surface-plated with a precious metal. For example, gold-plated items may conduct electricity differently than solid gold, revealing the presence of a non-precious metal core.

Complementary to Other Tests: While electrical conductivity provides valuable insights, it works best in conjunction with other testing methods, such as visual inspection, density measurement, and scientific testing, to form a more complete picture of the item’s authenticity.

In summary, electrical conductivity testing is a reliable, non-invasive method that helps identify metal composition and authenticity, detect counterfeits, and verify purity, making it an essential tool for anyone dealing in precious metals.

Electrical resistivity testing of bullion offers a scientifically accurate method to determine the composition and authenticity of metals by measuring how much a material resists the flow of electric current. The benefits of this type of testing are similar to those of electrical conductivity testing, but focus on the inverse property — resistance rather than conductivity. Here are the key benefits:

Precise Metal Identification: Every metal has a unique resistivity value. Precious metals like gold, silver, and platinum have low resistivity, while non-precious metals like tungsten, nickel, or alloys have higher resistivity. Measuring electrical resistivity helps accurately identify whether the tested metal is what it’s claimed to be.

Detecting Impurities and Alloys: Resistivity testing is particularly useful in detecting variations in metal composition. For example, gold that has been alloyed with other metals (e.g., in lower-karat gold) will show a different resistivity compared to pure gold. This helps in verifying both the purity and composition of the metal.

Non-Destructive: Like conductivity testing, resistivity testing is non-destructive. It allows for a reliable analysis of the item without causing any damage, which is important for high-value pieces.

Identifying Counterfeits: Counterfeit items often use metals with higher resistivity values compared to authentic precious metals. For example, base metals used in counterfeit bullion or jewelry may have significantly higher resistivity, making it easy to identify fakes. This method can detect counterfeit pieces even if they are surface-plated with a thin layer of precious metal.

Verifying Thickness and Purity of Plated Metals: Resistivity testing can help determine whether an item is solid metal or just surface-plated. For example, a gold-plated object may exhibit high resistivity beneath the plating layer, indicating the presence of a non-precious core. This is useful in detecting fraud where only the surface is coated with precious metal, while the interior is a cheaper metal.

Complementary to Other Tests: Electrical resistivity testing works well alongside other methods like visual inspection, density measurement, and scientific tests (e.g., X-ray fluorescence). It enhances the overall accuracy and reliability of a comprehensive metal analysis.

In summary, electrical resistivity testing provides an efficient, non-destructive way to detect counterfeit items, verify metal purity, and identify whether an item is solid or plated, all while ensuring that valuable pieces are not damaged during the process.

Conducting electrical resistivity through-metal testing of bullion involves measuring how much the entire bulk of a metal object resists the flow of electrical current. This testing goes beyond just surface evaluation and provides a deeper insight into the internal composition and structure of the metal. The key benefits of this method include:

Comprehensive Metal Composition Analysis: Through-metal resistivity testing measures the resistivity across the entire metal piece, not just its surface. This ensures that the metal’s core composition is consistent with its outer appearance, providing a more thorough analysis for detecting issues like internal impurities or alloying that may not be visible on the surface.

Detection of Counterfeits and Plated Items: One of the most significant benefits is the ability to detect counterfeit bullion that may be plated with a thin layer of precious metal while containing a cheaper, high-resistivity metal at its core. For example, gold or silver plating over tungsten or lead can easily be identified since the through-metal resistivity will be much higher than pure gold or silver.

Verification of Metal Purity: Through-metal resistivity testing helps verify the purity of the metal by detecting whether it’s mixed with other metals (alloys) throughout the piece. For example, pure gold has a specific resistivity value, and deviations from this can indicate that the gold is alloyed with other metals like copper or silver. This is especially useful for testing bullion bars or coins, where internal purity matters.

Non-Destructive: Like surface resistivity testing, through-metal resistivity testing is non-destructive, meaning the item remains intact and undamaged. This is particularly important for high-value pieces, where preservation is critical.

Detection of Voids and Internal Defects: Through-metal testing can reveal internal voids, inconsistencies, or defects in the metal that surface testing might miss. For example, some counterfeit items are hollow or contain non-metal fillers that may not be detected by surface tests alone. Resistivity testing through the entire metal piece can detect such inconsistencies.

Suitable for Large Pieces: Larger items like bullion bars or thick jewelry pieces benefit from through-metal resistivity testing, as it ensures that the internal composition matches the external appearance. Surface testing may not be sufficient for these larger items, especially if counterfeiting or fraud involves altering the interior structure.

Complementary to Other Tests: Like surface resistivity or conductivity testing, through-metal resistivity testing is most effective when used in combination with other tests such as X-ray fluorescence (XRF), visual inspection, or density analysis. Together, these methods provide a comprehensive verification of both surface and internal composition.

In summary, through-metal resistivity testing offers a thorough, non-invasive way to verify the entire internal and external composition of jewelry and bullion. It is highly effective at detecting counterfeits, ensuring purity, and identifying internal defects, making it a valuable tool for ensuring the authenticity and value of high-value precious metal items.

X-ray fluorescence (XRF) testing is a powerful analytical method used to determine the elemental composition of materials, including jewelry and bullion. Here are the key benefits of using XRF testing:

Precise Elemental Analysis: XRF provides accurate and detailed information about the elemental composition of metals. It can identify and quantify multiple elements in a sample, including precious metals (gold, silver, platinum) and base metals (copper, nickel, etc.), with high precision.

Non-Destructive: XRF testing does not damage or alter the item being tested. It works by measuring the fluorescent X-rays emitted from a sample when it is exposed to an X-ray beam, making it ideal for valuable jewelry, collectible coins, and bullion.

Immediate Results: The XRF testing process is relatively quick, providing immediate results. This is advantageous in settings where rapid verification is needed, such as in retail environments, auctions, or when assessing large quantities of bullion.

Comprehensive Analysis: XRF can analyze the entire metal composition, including detecting trace elements and impurities that might not be visible through surface testing. This helps in verifying both the purity and the presence of any alloying or contaminant elements.

Detection of Counterfeits and Fakes: XRF is highly effective in identifying counterfeit items or fraudulent claims about the metal’s purity. It can distinguish between genuine precious metals and those that are plated or alloyed with base metals, ensuring the authenticity of the item.

Verification of Metal Purity: XRF testing can accurately measure the purity of precious metals like gold and silver. For example, it can confirm whether a piece is 24k gold or if it is alloyed with other metals, providing crucial information for buyers and sellers.

No Sample Preparation Required: XRF testing typically requires minimal to no sample preparation, making it a convenient option for testing items in their original state. This reduces the time and effort needed for testing and maintains the integrity of the item.

Portable and Versatile: Portable XRF devices are available, allowing for on-site testing in various locations such as jewelry stores, trade shows, or during private transactions. This flexibility makes it easier to conduct tests without the need for sending items to a lab.

Data Documentation: XRF machines often come with software that records and documents test results. This provides a reliable record of the analysis that can be used for verification purposes, disputes, or for maintaining records of inventory.

Regulatory Compliance: XRF testing helps ensure compliance with industry regulations and standards related to metal purity and authenticity, which is crucial for businesses dealing with precious metals.

Judith Capital uses silicon drift detector (SDD) XRF, being superior to silicon PIN detector (Si-PIN). In XRF analysis, silicon drift detectors (SDDs) and silicon PIN detectors are two common types of detectors used for measuring emitted X-rays. Each has its strengths, but SDDs are often considered superior to Si-PIN detectors in several key aspects. Here’s why:

Higher Resolution: Silicon Drift Detectors (SDDs) typically offer better energy resolution compared to Si-PIN detectors. This means they can more accurately distinguish between X-rays of different energies, leading to more precise identification and quantification of elements. While Si-PIN detectors also provide good resolution, they generally lag behind SDDs in terms of resolving power. This can limit their ability to differentiate between elements with closely spaced X-ray emission lines.

Faster Detection: SDDs have a faster response time and higher count rates, allowing for quicker data acquisition. This is particularly beneficial when analyzing samples with low X-ray counts or when high-throughput analysis is required. Si-PIN detectors can be slower in terms of response time and may have lower count rates, which can result in longer analysis times and reduced efficiency in high-throughput environments.

Better Sensitivity: SDDs typically have higher sensitivity and lower noise levels. This means they can detect lower concentrations of elements more effectively and provide more reliable results, especially for trace element analysis. Si-PIN detectors generally have lower sensitivity and higher noise, which can affect their ability to detect trace elements and reduce the accuracy of measurements.

Improved Signal-to-Noise Ratio: Due to their design and higher sensitivity, SDDs often have a better signal-to-noise ratio. This leads to clearer and more accurate spectra, which is essential for precise elemental analysis and quantification. Si-PIN detectors may have a lower signal-to-noise ratio, which can affect the quality of the data and the accuracy of the elemental analysis.

Enhanced Performance in Low X-ray Energy Range: SDDs are particularly effective in detecting low-energy X-rays, which are important for analyzing elements with low atomic numbers. This capability enhances their versatility and effectiveness in a wider range of applications. Si-PIN detectors may be less effective in the low-energy X-ray range, potentially limiting their ability to analyze certain elements and reducing their overall analytical performance.

Compact Design: SDDs often have a more compact design compared to Si-PIN detectors, which allows for more flexible and portable XRF instrument designs. This compactness can also contribute to better overall system performance and efficiency. Si-PIN detectors may be larger and less flexible in terms of instrument design, which can impact the overall system setup and portability.

In summary, XRF testing offers precise, non-destructive, and immediate analysis of the elemental composition of jewelry and bullion. It is an essential tool for verifying authenticity, determining purity, detecting counterfeits, and ensuring compliance with industry standards, making it highly valuable in both retail and trade environments. Silicon drift detectors (SDDs) generally offer superior energy resolution, faster response times, higher sensitivity, and better performance in the low X-ray energy range compared to silicon PIN detectors (Si-PIN). These advantages make SDDs particularly well-suited for high-precision XRF applications, where accurate identification and quantification of elements are crucial.

Temperature-compensated density (purity) determination is a specialized testing method used to measure the density of jewelry and bullion, and it offers several key benefits:

Accurate Purity Assessment: The density of a metal is directly related to its purity. Precious metals like gold, silver, and platinum have specific densities, and variations from these values can indicate the presence of alloys or impurities. Temperature-compensated density testing provides an accurate measurement of density, allowing for precise determination of metal purity.

Account for Temperature Variations: Density measurements can be affected by temperature changes, as metals expand or contract with temperature fluctuations. Temperature-compensated density testing adjusts for these variations, ensuring that density measurements remain accurate regardless of environmental conditions. This is crucial for achieving reliable results in varying temperatures.

Non-Destructive: This method is non-destructive, meaning it does not alter or damage the jewelry or bullion being tested. This is especially important for high-value items or collectible pieces where preserving the item’s condition is essential.

Identify Fraudulent Pieces: Counterfeit items or those with plating may have different densities compared to the claimed precious metal. For example, gold-plated items or bullion with a base metal core will have a different density than pure gold or silver. Temperature-compensated density testing can reveal discrepancies and help identify fraudulent or misrepresented items.

Verification of Alloy Composition: The method can also be used to analyze the composition of metal alloys. By determining the density and comparing it to known densities of various alloys, it is possible to infer the composition of the alloy and ensure it meets the specified purity standards.

Maintain Standards: In manufacturing and trading of jewelry and bullion, maintaining high standards of quality is crucial. Temperature-compensated density testing helps ensure that products meet the required purity and quality specifications, contributing to overall product integrity and customer trust.

Complementary to Other Tests: This testing method complements other techniques like XRF, conductivity, or visual inspection. Using multiple methods provides a more comprehensive assessment of the item’s authenticity and purity.

In summary, temperature-compensated density (purity) determination offers accurate, non-destructive, and reliable measurement of metal density while accounting for temperature variations. It is an effective tool for verifying metal purity, detecting counterfeits, analyzing alloys, and maintaining quality control in the jewelry and bullion industry.

Ultrasonic thickness testing (UTT) is a valuable tool for inspecting bullion bars, particularly for detecting fraudulent inserts or verifying the uniformity of the bar’s composition. Here are the key benefits of using UTT for this purpose:

Detection of Fraudulent Inserts: UTT measures the thickness of the bullion bar at different points. If a fraudulent insert (such as a cheaper metal) is hidden inside the bar, it may cause inconsistencies in the thickness. Any significant deviation in thickness can suggest the presence of a non-precious core or voids within the bar.

Non-Destructive: Ultrasonic thickness testing is a non-invasive method, meaning it doesn’t damage or alter the bullion bar in any way. This is important for high-value bullion, as preserving the item’s original condition is essential during inspection.

Quick and Efficient: UTT provides quick measurements of the thickness across various points on the bar. This allows for fast, efficient inspections, making it ideal for situations where a large number of bullion bars need to be tested in a short amount of time.

Identify Hollow or Thin Areas: A bullion bar with fraudulent inserts might contain hollow spaces or thin layers of precious metal over a cheaper core. UTT can detect these hollow areas by identifying unexpected drops in thickness across the bar, indicating that the internal structure is not uniform.

Portable: UTT devices are generally portable, making them suitable for use in the field, at storage facilities, or during on-site inspections. This flexibility makes it convenient for quick inspections of bullion bars in various settings.

Reliable for Surface-to-Surface Verification: UTT can confirm that the thickness of the bullion bar is consistent across its surface. For example, a fraudulent bar might be thicker in some areas to compensate for a thinner layer of precious metal over a cheaper material. UTT identifies these variations, helping to ensure the bar is solid and genuine.

Complementary to Other Tests: UTT is often used in combination with other testing methods like XRF or ultrasonic flaw detection to provide a more comprehensive analysis. While UTT measures thickness, other methods can confirm the metal’s composition, further verifying the bar’s authenticity.

Effective for Various Metal Types: UTT can be used on various types of precious metal bullion, including gold, silver, platinum, and palladium. Its versatility makes it applicable to different metals, ensuring consistent results across a wide range of bullion products.

Detection of Major Anomalies: While UTT might not detect fine internal features like small voids or cracks (which are better identified through full ultrasonic testing), it is effective at detecting large-scale fraud where a significant portion of the bar is not composed of the claimed material.

In summary, ultrasonic thickness testing is a non-destructive way to detect fraudulent inserts and verify the structural integrity of bullion bars. It quickly measures the thickness of the bar, revealing inconsistencies that could indicate hidden non-precious metals or hollow spaces. UTT is portable, making it ideal for fast, on-site inspections. When combined with other testing methods, it provides an additional layer of security in verifying the authenticity of bullion.

Thermal conductivity testing is a widely used method for evaluating diamonds, and it offers several distinct benefits:

Accurate Identification of Diamonds: Thermal conductivity testing is highly effective in distinguishing genuine diamonds from diamond simulants or imitations like cubic zirconia or moissanite. Diamonds have a unique thermal conductivity that is significantly higher than most other gemstones. This property allows the test to accurately identify diamonds.

Non-Destructive: Thermal conductivity testing is non-invasive and does not damage or alter the gemstone. This is crucial for preserving the integrity and value of the diamond, especially when dealing with high-value or delicate stones.

High Sensitivity: Thermal conductivity testers are highly sensitive and can detect even slight differences in thermal properties. This high sensitivity ensures accurate identification of diamonds, including distinguishing between natural diamonds and high-quality synthetic diamonds.

Consistency Across Different Conditions: The method performs consistently across different environmental conditions, such as temperature variations and lighting. This reliability makes it a dependable tool for gemologists and jewelers.

Complementary to Other Tests: While thermal conductivity testing is highly effective, it is often used in conjunction with other testing methods, such as visual inspection, UV fluorescence, or spectroscopy. Combining these methods provides a more comprehensive assessment of the diamond’s authenticity and quality.

In summary, thermal conductivity testing offers accurate, non-destructive, and rapid identification of diamonds by measuring their unique thermal properties. It effectively distinguishes genuine diamonds from simulants, provides reliable results, and is an essential tool for gemologists, jewelers, and anyone involved in the diamond trade.

Ultraviolet fluorescence testing is a valuable method for evaluating diamonds and can be particularly useful for identifying lab-grown diamonds and simulants. Here are the key benefits of this testing method:

Distinguishing Lab-Grown Diamonds from Natural Diamonds: Natural diamonds and lab-grown diamonds often exhibit different fluorescence patterns under UV light. For instance, natural diamonds may show various fluorescence colors and intensities, while lab-grown diamonds, especially those created by the High-Pressure High-Temperature (HPHT) or Chemical Vapor Deposition (CVD) methods, might exhibit specific fluorescence characteristics or sometimes show no fluorescence at all. This helps in distinguishing between natural and lab-grown diamonds.

Identifying Diamond Simulants: Many diamond simulants, such as cubic zirconia and moissanite, react differently to UV light compared to natural diamonds. For example, cubic zirconia may exhibit a distinct fluorescence pattern or color under UV light that differs from that of genuine diamonds. This difference aids in identifying simulants and verifying the authenticity of the gemstone.

Non-Destructive: Ultraviolet fluorescence testing is a non-invasive method that does not damage or alter the gemstone. This is crucial for preserving the value and integrity of high-value diamonds and other gemstones during testing.

Complementary to Other Tests: While UV fluorescence testing is effective, it is often used alongside other methods such as thermal conductivity testing, visual inspection, and spectroscopy. Combining these tests provides a more comprehensive analysis of the gemstone’s authenticity and origin.

Detection of Treatments: UV fluorescence can sometimes help identify certain treatments applied to diamonds, such as high-temperature annealing, which may alter the fluorescence pattern. This can provide additional information about the diamond’s treatment history.

Effective for Varied Types of Diamonds: UV fluorescence testing is effective for a wide range of diamonds, including those with different color grades and sizes. It can be used to assess both high-quality and lower-grade diamonds, making it a versatile tool in gemology.

In summary, ultraviolet fluorescence testing offers an efficient, non-destructive way to identify lab-grown diamonds and simulants by revealing their unique fluorescence patterns. It helps distinguish between natural and lab-grown diamonds, spot diamond simulants, and provides additional insights into the gemstone’s characteristics. When used alongside other testing methods, it contributes to a thorough and accurate assessment of diamonds and gemstones.