Internal Continuity
Assess whether returning signals are consistent with the expected internal path through a suitable solid bar.
Gold Authentication Method
Ultrasonic Gold Bar Testing
Non-Destructive Internal Examination of Suitable Bullion
Ultrasonic testing introduces sound waves into a suitable solid bar and analyses returning signals for information about internal continuity.
It is an authentication and internal-integrity examination—not an assay for exact gold fineness.
Bilex confirms whether the item geometry, surface and available reference conditions make ultrasonic examination appropriate.
Bilex Sample Handling
What Ultrasonic Examination Can Show
An ultrasonic probe sends sound into a suitable solid item and receives reflected signals. Reflections may indicate the far surface, internal boundaries, discontinuities, voids or foreign inclusions that affect sound propagation.
The method preserves the bar and can add evidence about internal structure that a surface-composition measurement cannot provide. It should be interpreted alongside the item geometry, casting characteristics, calibration and other relevant examination results.
Ultrasonic examination does not determine exact gold fineness. An apparently consistent response does not by itself establish the analytical gold content of a bar, and the method must not be promoted as a guarantee against every counterfeit construction.
Analytical purpose
What Ultrasonic Gold Bar Testing Can Help Determine
The method is selected from the material and the analytical question—not from a claim that one technology is best for every sample.
Discontinuities
Identify reflections that may be associated with boundaries, voids or inclusions requiring review.
Large Cast Bars
Examine suitable cast bullion where geometry and surface condition support ultrasonic coupling.
Complementary Evidence
Combine internal-structure information with surface, physical or analytical evidence as appropriate.
Suitable Materials
Suitability is confirmed against the sample form, expected composition and applicable analytical procedure.
- Suitable cast gold bars
- Large bullion bars
- Selected solid doré bars where appropriate
- Other suitable solid items with workable geometry and surfaces
Before testing
Sample & Preparation Requirements
- The item must be a suitable solid form; ore, powder, concentrate and loose nugget parcels are not appropriate for bar ultrasound.
- Geometry, accessible surfaces, coupling, calibration and reference conditions affect whether useful signals can be obtained.
- Casting porosity or legitimate metallurgical features can create responses that require careful interpretation rather than automatic rejection.
- Bilex confirms equipment availability, operator scope and reporting terminology before arranging the examination.
Main Strengths
- Non-destructive internal examination
- Can indicate boundaries, discontinuities, voids or inclusions
- Adds evidence that surface-only methods cannot provide
- Suitable results can be retained for review and comparison
Important Limitations
- Does not determine exact fineness
- Does not guarantee detection of every counterfeit or anomaly
- Requires suitable geometry, surfaces, equipment and calibration
- Legitimate casting features can affect responses
- Not applicable to loose, powdered or granular material
Method selection
Compare Related Testing Methods
Different methods provide different kinds of evidence. Complementary testing may be appropriate where one result cannot answer the full question.
Ultrasound and XRF
XRF examines elemental composition in selected surface regions. Ultrasound examines how sound travels through the internal structure of a suitable solid bar.
They provide different evidence and may be complementary, but neither alone establishes representative bulk fineness of a thick bar.
Ultrasound and Fire Assay
Ultrasound preserves the item and examines internal integrity. Fire Assay determines gold from an appropriate representative analytical portion and consumes that portion.
If exact fineness is the question, ultrasonic consistency should not be substituted for an appropriate analytical determination.
A Result Represents the Sample Actually Tested
The analytical result describes the identified sample and stated method. Applying that result to a bar, parcel, shipment or multi-kilogram lot depends on whether the sampling procedure reasonably connects the tested sample to the defined material.
Testing does not by itself establish ownership, lawful origin, seller legitimacy, export authorisation or payment security.
Common questions
Ultrasonic Gold Bar Testing FAQ
Does ultrasound determine gold purity?
No. It provides internal structural information and does not determine exact gold fineness.
Can ultrasound detect material inside a gold bar?
Reflections can indicate internal boundaries, voids or foreign inclusions, but interpretation depends on equipment, calibration, geometry and legitimate casting features.
Is ultrasonic testing destructive?
The examination is normally non-destructive for a suitable item and does not require removing an analytical portion.
Can ultrasound replace Fire Assay?
No. Ultrasound examines internal structure; Fire Assay determines gold in a representative prepared analytical portion.
Why might ultrasound and XRF be used together?
XRF adds surface elemental information while ultrasound adds internal structural evidence. Together they answer more than either examination alone, but they do not automatically establish bulk fineness.
Gold Testing & Assaying
Related Testing Methods
Use these links to compare the evidence each method can provide before selecting an analytical approach.
010203
XRF Analysis
Combine internal structural review with selected surface-region elemental evidence.
Learn MoreDensity Testing
Add supporting information about the item's overall physical consistency.
Learn MoreFire Assay
Understand representative analytical determination where sample removal is permitted.
Learn MoreGold Authentication Method
Discuss Your Sample Before Testing
Tell Bilex what material you have, what you need to establish, whether the item must remain intact and how the result will be used. The team will review method suitability and confirm the next step.
Method availability, equipment or partner-facility arrangement, sample requirements, timing and reporting scope are confirmed for the specific enquiry.