Credible stones.
Credible certificates.
Independent testing and certification for diamonds and precious stones. Results that hold up in commercial transactions, export documentation, and legal reviews.
A gemstone without a certificate
is worth whatever someone decides to offer you.
A certified gemstone is worth what it actually is.
Uganda produces diamonds, rubies, sapphires, emeralds, and a range of precious and semi-precious stones. Many of them pass through the market at prices far below their actual value, not because the stones are not valuable, but because the people selling them have no certified documentation to support the price they should be asking.
An informal opinion from a dealer, a verbal estimate at a market, or even a letter from an uncertified source does not constitute a gemstone certificate in the markets that serious buyers operate in. International buyers, insurance companies, legal valuations, and export compliance processes all require the same thing: a formal, certified assessment from a licensed, accountable testing operation.
Maxmetal's gemstone testing and certification service produces exactly that. An independent assessment of your stone's identity, quality characteristics, and certified classification, documented in a formal certificate that states the methodology used, the results produced, the chain-of-custody reference, and the authority of the operation that issued it.
The certificate does not make your stone more valuable. It makes its value knowable, in writing, to any buyer, in any market. That is what changes the commercial conversation.
Gemstone certification at Maxmetal serves everyone
who needs to know what their stone is actually worth.
Miners & Artisanal Gemstone Producers
You have rough or polished stones and you need certified documentation before you sell.
Without a certificate, your gemstone is worth whatever a buyer tells you. With a Maxmetal certification, you bring a documented, verified determination to the negotiation, and the conversation starts from a real number, not an offer.
Submit a Stone for TestingDealers & Gemstone Traders
You are buying, selling, or trading gemstones and need documentation your buyers will accept.
A Maxmetal certificate gives your stones a documented identity and quality classification that serious buyers recognise as credible. It protects your position in every transaction and builds the kind of trading reputation that informal dealing cannot.
Discuss Your RequirementsExport Clients & International Sellers
You are preparing a gemstone consignment for export and need certification that holds up at the destination.
Our certification documentation is produced to the standard that international gemstone buyers, export agencies, and destination market compliance frameworks require. What leaves Uganda with a Maxmetal certificate arrives at its destination with documentation that does not raise questions.
Contact Our TeamPrivate Clients & Estate Holders
You have a stone or a collection that needs a formal, independent valuation for legal, insurance, or estate purposes.
Whether you are settling an estate, preparing for an insurance claim, entering a legal process, or simply establishing the documented value of a stone you own, Maxmetal provides an independent, certified assessment from a licensed operation.
Request a Private AssessmentGemstone testing is the scientific determination of what a stone is and what it contains.
A gemstone certificate is the output of a structured, multi-stage testing process, not a single measurement, not a visual assessment, and not an expert opinion expressed informally. It is the result of applying specific analytical instruments and certified methodologies to determine a stone's identity, its key quality characteristics, and its classification against established gemological standards.
At the foundational level, testing determines what species the stone is, whether a transparent blue stone is a sapphire, an aquamarine, a blue topaz, or a synthetic substitute. That identification alone is commercially critical, because stones that look similar can vary enormously in value, and a buyer who cannot verify identity will price that uncertainty into their offer.
Beyond identification, professional gemstone testing assesses the quality characteristics that drive commercial value: for diamonds, the internationally recognised grading parameters of cut, clarity, colour, and carat weight. For coloured stones, rubies, sapphires, emeralds, and others, the equivalent quality assessments specific to each species, including colour saturation, clarity, and any treatments the stone has undergone.
Treatment disclosure is one of the most commercially significant aspects of gemstone certification. Heat treatment, fracture filling, and other enhancement techniques are widely used in the gemstone trade and they affect value substantially. A certified assessment that discloses treatment status gives a buyer complete information, and protects a seller against the accusation of concealment after a transaction is complete.
At Maxmetal, every gemstone testing engagement produces a certificate that contains the species identification, the quality assessment, the treatment status determination, the weight, and the chain-of-custody reference. The result is a complete document that answers every question a serious buyer, insurer, or legal process will ask about the stone.
- Gemstones Tested
- Diamonds, rubies, sapphires, emeralds, and precious and semi-precious stones, confirmed at intake consultation
- Assessment Parameters
- Species identification, quality grading, treatment status disclosure, weight, and classification, specific parameters confirmed based on stone type
- Output Formats
- Gemstone certificate with species identification, quality assessment, treatment disclosure, weight, chain-of-custody reference, and DGSM license reference
- Stone Conditions Accepted
- Rough, polished, and mounted stones, mounting removal may be required for complete assessment in some cases, confirmed at intake
- Documentation Produced
- Gemstone certificate, assessment methodology notes, chain-of-custody record, intake receipt
- Licensing
- Active DGSM Mineral Dealer License, independently verifiable through Uganda's MCRS portal
- Turnaround
- Confirmed at intake based on stone type, assessment complexity, and current schedule
From intake to certified result.
Every gemstone testing engagement at Maxmetal follows a documented process, from the moment your stone is received to the moment your certificate is issued. Nothing about the process is informal. Nothing about the result is approximate.
Your stone is received, described, and formally documented in its current condition.
At intake, your gemstone is examined, described, and recorded in detail, species if already known, approximate weight, any visible characteristics, and the condition of the stone on arrival. If your stone is mounted, the mount condition and any relevant features are noted. You receive a signed, dated intake receipt before the stone moves to testing.
The intake condition record is the baseline against which the full assessment is measured, and the document that confirms, unambiguously, what you handed over and when.
Your stone is examined under magnification to establish its initial characteristics.
The preliminary examination uses standard gemological instruments to assess the stone's basic visual characteristics, transparency, colour, inclusions visible under magnification, surface condition, and any obvious signs of treatment or enhancement. This stage determines the scope of testing required and confirms whether any additional instruments or procedures need to be applied.
Your stone is tested using certified instruments to determine its identity and properties.
Instrumental testing uses refractometers, spectroscopes, polariscopes, and other certified gemological instruments to measure the physical and optical properties of the stone, the properties that determine its species, its variety, and its treatment status. This is the stage that distinguishes a natural ruby from a synthetic one, a heat-treated sapphire from an untreated one, a genuine diamond from a simulant. The results of each instrument are recorded as part of the assessment documentation.
Your stone's quality characteristics are assessed against established gemological standards.
Based on the species identification and instrumental testing results, the stone's quality characteristics are graded against the relevant standard for that species, the four Cs for diamonds, the colour-clarity-treatment framework for coloured stones. Weight is confirmed on certified scales. Treatment status is documented based on the testing results. The complete quality profile of the stone is assembled at this stage before the certificate is drafted.
Your certified gemstone certificate and complete documentation are returned to you.
Your gemstone certificate, containing the species identification, quality grading, treatment disclosure, certified weight, chain-of-custody reference, and our DGSM license reference, is issued and returned to you along with your stone. The certificate is a formal, signed document. The methodology that produced every determination on it is documented. Every statement on it is defensible.
A Maxmetal gemstone certificate.
Complete, signed, and built to hold up.
Client name and contact details
The legal identity of the stone's owner as recorded at intake.
Stone reference number
The chain-of-custody identifier connecting this certificate to every document produced during the assessment.
Species identification
The certified determination of what the stone is, its mineral species, variety, and any relevant geographical origin information if determinable.
Weight
The certified carat weight of the stone, measured on certified scales.
Quality characteristics
The grading assessment of the stone's quality parameters, cut, colour, clarity, and carat for diamonds; colour saturation, clarity, and quality grade for coloured stones.
Treatment status
The certified disclosure of any treatments or enhancements identified during testing, heat treatment, fracture filling, or other enhancement techniques. If no treatment is detected, that is stated explicitly.
Testing methodology
The instruments and procedures applied during the assessment, documented so the determination can be reviewed, audited, or independently evaluated.
DGSM license reference
Our active mineral dealer license number, independently verifiable through Uganda's Mining Cadastre and Registry System.
Date of issue and authorising signature
The date the certificate was produced and the signature of the Maxmetal authorised signatory accountable for the assessment.
A gemstone certificate that omits the testing methodology, the treatment disclosure, or the issuing authority's credentials is not a complete document. In a commercial transaction, an incomplete certificate is a liability, it raises the questions it was supposed to answer. In a legal context, an incomplete certificate is often inadmissible. In an insurance valuation, it may be insufficient to support a claim.
Maxmetal's gemstone certificates are produced to be complete on their face. Every element that a buyer, an insurer, an export agency, or a legal process will look for is present before the certificate leaves our operation. You should never have to call us to explain what is on your certificate. It explains itself.
Most gemstones have been treated.
The certificate should say so.
Ours does.
Treatment disclosure is not a comfortable topic in some parts of the gemstone trade, because the presence of treatment generally reduces a stone's value relative to an equivalent untreated stone. But in the markets that serious buyers operate in, international gemstone dealers, certified jewellers, insurance companies, and institutional buyers, the absence of treatment disclosure on a certificate is not a reassurance. It is a red flag.
A certificate that does not address treatment status leaves the buyer with one of two conclusions: either the testing operation did not test for treatments, which raises questions about the completeness of the assessment, or treatments were found and not disclosed, which raises questions about the integrity of the issuing operation. Neither conclusion is good for the seller.
At Maxmetal, treatment testing is part of every gemstone assessment, not an optional add-on. If a treatment is present, the certificate states it. If no treatment is detected, the certificate states that too. The seller who holds a Maxmetal certificate that confirms a stone is untreated has a document that commands a premium, because the disclosure was independent, certified, and complete. The seller whose stone shows treatment has a document that is honest, and an honest document is more commercially durable than one that raises questions later.
Treatment Disclosure Reference
Heat Treatment
Very common in coloured stones. Generally accepted in the trade but must be disclosed. Untreated equivalent commands a significant premium.
Fracture Filling
Improves apparent clarity artificially. Substantially reduces value relative to naturally clear equivalent. Must be disclosed.
Surface Coating
Applied to enhance colour. Not permanent. Significantly reduces value and must be disclosed.
No Treatment Detected
Commands a market premium, particularly for rubies, sapphires, and emeralds. A certified untreated declaration from a licensed operation is a commercial asset.
Gemstone certification for export.
Built to arrive intact.
International gemstone buyers and destination market compliance frameworks have specific documentation requirements. A certificate that satisfies a local Ugandan transaction may not satisfy a buyer in Antwerp, Bangkok, or New York. The differences are not minor, they involve the completeness of the grading parameters, the treatment disclosure protocol, the methodology transparency, and the verifiability of the issuing authority.
Maxmetal's gemstone certificates are produced with international buyer requirements in mind from the start. The species identification follows standard gemological nomenclature. The quality grading uses internationally recognised frameworks. The treatment disclosure is explicit. The DGSM license reference is independently verifiable. These are not features we add when an export client asks for them. They are the standard certificate format.
If your specific buyer or destination market has stated documentation requirements that go beyond our standard certificate, bring them to us in writing before your stone enters the testing process. We confirm whether we can meet them. If we can, we build them in. If we cannot, we tell you before your stone is submitted, not after your certificate has been issued.
For export consignments involving multiple stones, we produce individual certificates for each stone and a consolidated consignment summary that your export documentation process can reference. The chain-of-custody record covers the full lot from intake to the point at which each stone and its certificate are returned to you.
A certified assessment for the conversation
that cannot afford ambiguity.
Some of the most important moments when a gemstone certificate matters have nothing to do with a commercial sale. An estate being settled among beneficiaries needs an independent, certified valuation that none of the parties can credibly dispute. An insurance claim requires documentation that the insurer's assessors will accept as evidence of the stone's value at the time of loss. A legal process involving a mineral asset needs a formal determination from a licensed authority that the court will recognise.
In all of these contexts, the question is not just what the stone is worth. It is who certified that worth, under what authority, using what methodology. An informal opinion, however expert, does not answer those questions. A Maxmetal certificate does.
We approach private client and estate engagements with the same rigour we apply to every commercial consignment, and with a specific awareness that the context matters. If your certificate is for an insurance purpose, we produce it with insurance documentation requirements in mind. If it is for a legal process, we produce it with the specificity that a legal review requires. Tell us at intake what the certificate is for, and we produce a document built for that purpose.
Common Use Cases
Estate Settlement
An independent certified determination of gemstone value that all parties can rely on without contesting the source.
Insurance Valuation
Formal documentation of a stone's identity, quality, and certified value for insurance purposes, produced to the standard insurers require.
Legal Proceedings
A certified assessment from a licensed, regulated operation that carries the documentary weight a legal process requires.
Pre-Sale Verification
An independent assessment before a private sale, so you know what your stone is worth before you agree to any price.
Collection Assessment
Formal certification of a gemstone collection, individual certificates per stone and a consolidated collection summary.
The questions we hear before a gemstone testing engagement begins.
We test diamonds, rubies, sapphires, emeralds, and the range of precious and semi-precious stones found in Uganda's mineral sector. If you have a stone you are not certain we cover, contact us before you come in. We will tell you directly whether your specific stone falls within our testing scope. We do not take a stone into the process and then discover we cannot complete the assessment.
We test both rough and polished stones. The testing approach and the parameters assessed differ slightly between rough and polished material, and we confirm the appropriate methodology at intake. If your stone is mounted in jewellery, note that some testing procedures require the stone to be removed from its mount for a complete assessment. We discuss this at intake and confirm whether mounting removal is necessary before the process begins.
Treatment testing uses a combination of spectroscopic analysis, microscopic examination, and other certified gemological instruments designed to detect the specific optical and physical signatures of treatment processes. The testing methodology for treatments is documented on your certificate alongside the treatment disclosure result. We test for treatments as a standard part of every gemstone assessment, not as an optional addition.
Our certificates are produced using standard gemological nomenclature, internationally recognised grading frameworks, and complete treatment disclosure, under active DGSM licensing with a verifiable license reference. For buyers in most international markets, this meets their documentation requirements. If your specific buyer has a stated standard, a particular grading system, a specific disclosure format, or a requirement for a particular level of methodological detail, bring it to us before submission. We confirm whether we can meet it before your stone enters the process.
International gemological laboratories such as GIA, AGL, and Gübelin are globally recognised and produce certificates that carry established brand recognition in international wholesale and retail markets. A Maxmetal certificate is issued by a DGSM-licensed Ugandan operation and is specifically appropriate for transactions within Uganda's mineral market, export processes from Uganda, and commercial, legal, and insurance contexts in markets that accept Ugandan regulatory credentials. If your specific commercial context requires a certificate from an internationally recognised grading laboratory, we will tell you that directly rather than issuing a certificate that will not serve your purpose.
Bring your stone in the most secure packaging you have available, a small, sealed container or a padded pouch. If your stone has existing documentation from a previous assessment, bring it with you. At intake, your stone is examined in your presence before it is formally received, and its condition at the point of receipt is recorded. If you are unsure how to transport a particular stone safely, call us before you come in and we will advise you.
Every gemstone testing engagement at Maxmetal is conducted under active DGSM licensing and full regulatory compliance.
Our mineral dealer license is issued by Uganda's Directorate of Geological Survey and Mines and is independently verifiable through the MCRS portal. Our license reference appears on every gemstone certificate we issue. If your buyer, insurer, legal process, or due diligence procedure requires formal documentation of our regulatory standing, we provide it on request.
View Our Compliance & LicensingGemstone testing often connects to what comes next.
Assaying Services
If your consignment contains both gemstones and other minerals, our assaying service provides certified compositional analysis for the mineral components, under the same chain-of-custody documentation as the gemstone testing.
See Assaying ServicesMineral Consultancy
If your certified gemstone assessment raises questions about what to do next, whether to sell, hold, develop, or seek investment, our consultancy service provides expert guidance grounded in the result we produced.
See Mineral ConsultancyTransaction Handling
Once your gemstone is certified, our transaction handling service facilitates the commercial process, managing the sale on verified, documented terms so your certified stone reaches a buyer at its actual value.
See Transaction HandlingKnow what it is.
Know what it is worth.
Have it in writing.
Tell us what stone you have, what you need the certificate for, and any specific requirements your buyer, insurer, or legal process has stated. We will confirm the testing scope, the turnaround, and exactly what your certificate will contain, before your stone enters our process.