Phone:
(413) 214-6541
Location:
15 Agawam Ave West Springfield, MA 01089
Mon - Fri:
8.00am - 7.00pm
Parent Website:
sterlinganalytical.com
Precious Metal Assay Lab
Related Posts
Sterling Analytical operates a precious metal assay lab quantifying gold, silver, platinum, palladium, rhodium, and ruthenium across a broad range of source materials — ores, concentrates, scrap, industrial residues, and recovered metal streams. Our assay services support refiners, recyclers, traders, and mining operations who need accurate, defensible precious metal data for valuation, processing, and commercial settlement decisions.
Precious metal value concentrates in small fractions of a much larger material, which means the analytical method has to match the matrix and concentration level, not just the element being measured. A gold ore sample, a catalytic converter scrap lot, and a refinery sweep all behave differently during digestion or fire assay, and treating them the same way is one of the most common sources of inaccurate valuation in this industry. A digestion strategy tuned for silicate-hosted gold ore will not necessarily recover platinum group metals locked in a ceramic catalyst support, and a method validated for percent-level scrap can produce misleading results on a low-grade tailings sample.
This is why precious metal assay work is less about running a single instrument and more about matching preparation chemistry, instrumentation, and reporting approach to the specific material in front of us. We combine ICP-OES, ICP-MS, and fire assay capability under one roof, so the method is chosen to fit your material and your decision — not the other way around.
Whether you’re screening incoming material at a recycling facility, verifying a refiner’s reported yield, or settling a transaction where both sides need a number they can trust, the underlying question is the same: does this result reflect what’s actually in the material, or just what was easiest to measure?
Matrix & Method Selection
Precious metal assay accuracy depends heavily on getting two decisions right: how the sample is prepared, and which analytical technique fits the expected concentration range. Get either one wrong and the result can look clean while still understating real value — incomplete digestion leaves metal trapped in the matrix, and a method chosen for the wrong concentration range either buries the signal in noise or saturates the instrument.
Sterling Analytical applies digestion and assay strategies matched to material type:
- Multi-acid digestion (aqua regia-based) for dissolution of gold, silver, and platinum group metals from ores, concentrates, and scrap
- Hydrofluoric acid (HF) where required to fully open silicate or refractory ore matrices
- Oxidative treatment to break down organic or carbon-bearing material that can mask true metal content
- Fire assay collection for low-concentration ores and high-value settlement scenarios requiring maximum defensibility
Method selection depends on the source material, expected concentration, and whether the result needs to support routine evaluation or a binding commercial transaction. A screening sample for an internal blending decision doesn’t need the same level of rigor as a result that will be cited in a refining contract — and pricing should reflect that difference, not apply maximum rigor (and maximum cost) to every sample regardless of purpose.
Precious Metals Assayed
- Gold (Au) : Low ppm through wt%
- Silver (Ag) : Low ppm through wt%
- Platinum (Pt) : Low ppm through wt%
- Rhodium (Rh) : Low ppm through wt%
- Ruthenium (Ru) : Low ppm through wt%
We routinely quantify gold, silver, and the platinum group metals across ores, concentrates, scrap, and industrial residues, with detection capability from low ppm to percent levels depending on matrix and method. Additional elements, including base metal context, can be added depending on source material and processing requirements.
ICP-OES, ICP-MS, and Fire Assay: Choosing the Right Method
ICP-OES provides fast, multi-element quantification across a wide concentration range and is well suited to routine screening, technical evaluation, and process monitoring across most precious-metal-bearing materials.
ICP-MS extends detection into sub-ppm and ppb territory, useful for low-grade ores, environmental-adjacent screening, or applications where ultra-trace confirmation is required.
Fire assay remains the gold standard for low-concentration precious metal materials and high-value settlement scenarios — it is a collection technique designed to quantitatively capture precious metals prior to measurement, and is the method most counterparties expect to see behind a contractual valuation.
In practice, ICP-OES or ICP-MS is often used for primary screening and process decisions, with fire assay applied where maximum accuracy or contractual defensibility is required.
Common Valuation Problems We Identify
Across the materials we assay, certain issues come up repeatedly — and most of them trace back to preparation, not instrumentation:
- Underreported precious metal content due to incomplete digestion of refractory or encapsulating matrices
- Inconsistent results between labs caused by mismatched preparation methods for the same material type
- Sampling bias from non-representative subsamples on heterogeneous lots
- Discrepancies between screening-grade ICP results and contract-grade fire assay confirmation on the same material
- Base metal interferences that distort apparent precious metal concentration if not properly accounted for during method setup
Identifying which of these is at play often matters more than the headline number itself, since it determines whether a low result reflects the material or the method.
Who Uses This Service
- Refiners verifying incoming lot composition before purchase or processing
- Recyclers screening scrap, catalyst, and electronic waste streams to guide sorting and pricing
- Traders requiring independent, defensible assay data to support a transaction or settle a dispute
- Mining and exploration operations assaying ore and concentrate samples for resource evaluation
- Jewelry and electronics manufacturers verifying precious metal content in recovered or recycled material
Materials We Assay
Our precious metal assay lab supports a wide range of source materials, including:
- Gold and silver ores, concentrates, and tailings
- Platinum group metal ores and concentrates
- Catalytic converter and industrial catalyst scrap
- Electronic and jewelry scrap
- Refinery residues and process sweeps
- Recovered or recycled precious metal streams
Each material type is prepared according to its specific composition and expected metal concentration to ensure representative, defensible results. An ore sample dominated by silicate gangue, a catalyst scrap lot bound in a ceramic or alumina support, and a refinery sweep with high base metal content each require a different digestion strategy to recover the precious metal fraction completely — which is why we scope preparation per matrix rather than running a single standard procedure across every sample type.
Sampling & Submission Guidance
Precious metal distribution is rarely uniform across a lot, and sampling error is one of the largest sources of valuation disagreement in this industry — often larger than analytical error itself.
Recommended submission:
- 5–20 grams of well-mixed, representative material for most matrices
- Crushed or homogenized where practical, especially for ore or scrap lots with visible particle size variation
- Clearly labeled with material source, type, and any known processing history
- For high-value or disputed lots, larger composite sampling can be discussed to reduce valuation risk on both sides
Turnaround Time & Pricing
Standard turnaround: 3–5 business days Rush service: 24–48 hours available
Pricing depends on material type, element panel, and whether fire assay confirmation is required. Volume pricing is available for larger lots and routine assay programs.
All results are supported by CRM-traceable calibration, ensuring defensible data for recovery valuation and process decisions.
What You Receive
Clients receive a detailed analytical report suitable for technical evaluation, refining negotiations, and commercial settlement.
Your report includes:
- Precious metal concentration (ppm and wt%) via ICP-OES, ICP-MS, or fire assay
- Method summary and rationale for technique selection
- Reporting limits and analytical qualifiers
- Batch-level quality control checks (duplicates, spikes)
Methods & Standards
Sterling Analytical applies established methods adapted for precious metal assay across varied source materials:
- Microwave-assisted acid digestion (EPA 3052 framework)
- Aqua regia-based dissolution for gold, silver, and platinum group metals
- ICP-OES for multi-element quantification
- ICP-MS available where ultra-trace confirmation is required
- Fire assay collection available for low-concentration materials and high-value settlement scenarios
Related Services
Explore related services:
- Spent Catalyst Precious Metal Recovery
- Spent Catalyst Analysis
- Catalyst Impurity Testing
- Platinum Reforming Catalyst Testing
- Nickel & Cobalt Concentrate Assay
Request a Quote
Submit your material details to receive a fast quote and recommended analytical scope. We’ll confirm preparation approach, method selection, pricing, and turnaround based on your material type and expected precious metal content.
Frequently Asked Questions
A precious metal assay lab quantifies gold, silver, and platinum group metals across ores, concentrates, scrap, and industrial residues, supporting valuation, refining decisions, and commercial settlement.
ICP-OES handles routine multi-element screening across a wide concentration range. ICP-MS extends detection to sub-ppm and ppb levels for ultra-trace requirements. Fire assay is a collection technique used for low-concentration materials and high-value settlement scenarios requiring maximum defensibility.
Yes, though each material type is prepared and analyzed according to its specific composition, so submissions are typically scoped per matrix to ensure accurate, representative results.
The most common cause is mismatched preparation method rather than instrument disagreement — a digestion strategy that fully recovers metal from one matrix may underreport on another. Matching method to material is the single biggest factor in result consistency.
Yes. ICP-OES or ICP-MS is commonly used for initial screening, with fire assay applied as a confirmatory step where contractual defensibility or maximum accuracy is required.
Typically 5–20 grams of well-mixed, representative material for most matrices. For high-value or disputed lots, larger composite sampling can reduce valuation risk and is worth discussing before submission.
Standard turnaround is 3–5 business days, with 24–48 hour rush service available.
Yes. Reports are supported by CRM-traceable calibration and quality control data designed to stand up to scrutiny from counterparties or refiners.
Quick Contact
If you have any questions or need help, feel free to contact with our team.
Send Us Email:
Call Us Today: