Gold Assayer Near Me: How to Choose a Lab and Costs

A gold assayer is a laboratory chemist who measures how much gold a rock, concentrate or metal sample holds, almost always by fire assay. Published price lists show what that costs: a 30 g gold fire assay was listed at C$23.00 by Actlabs (schedule dated February 2026) and at $21.40 by Paragon Geochemical in Nevada (2025 schedule), before the crushing and grinding that every rock sample needs first. Hazen Research in Colorado reports routine results in 15 to 20 business days (fee schedule effective 1 July 2026). The sections below show the kinds of assayer you can hire, how to check one, what the work costs, how long it takes and how to avoid the sampling mistakes that spoil a result.

Two terms come up in every quote. A grade is the amount of gold in the rock, written in grams per tonne (g/t) or parts per million (ppm); the two units are the same number. A finish is the instrument step that measures the gold after the sample has been melted or dissolved.

What a gold assayer does

The assayer’s job is to turn a bag of rock into a number that a mine owner, a buyer or a bank will accept. The Nevada Bureau of Mines and Geology explains why that number matters: rock only counts as ore when it holds enough recoverable metal to sell for more than it costs to produce, and the assayer determines the amount of metal in the rock. The same page calls fire assaying the most common and reliable method for gold, silver and platinum-group metals.

At a gold mine the assayer works inside a site laboratory. The Nevada Division of Minerals career sheet describes an assayer as someone who assists with sample preparation, performs fire assaying, runs atomic absorption analysis, does basic assay calculations and fills out daily reports. The same document sets the entry bar at a high school diploma plus six months of fire assay and sample preparation experience, with written and hands-on tests on calculations, technique, reagents and safety. A gold mine assayer therefore feeds three decisions: which blasted rock goes to the mill, how much gold each day’s ore holds, and whether drill results justify more drilling.

In a commercial laboratory the day looks different. An Ontario career profile lists the routine: log samples into a laboratory information system, verify chain of custody, prepare samples by drying, crushing, splitting and pulverising, run each batch with blanks, duplicates and certified reference materials, then re-run anything that fails. It adds that this work is carried out under quality standards such as ISO/IEC 17025 (occupations.ca assayer profile). A certified reference material is a powder with a known, certified gold value that the lab must reproduce.

▶ How gold is mined and refined, from rock to ring, step by step. · 5:27

Gold assayers near me: five kinds and who needs which

The word “assayer” covers several different businesses. Pick the type that matches your sample before you compare prices.

Sources: Hazen Research, precious metals and fire assaying; Paragon rate book; IAS certificate TL-536; SCC scope of accreditation 15895; The Perth Mint refinery; Sheffield Assay Office.

For a prospector with a few rock samples, the first row is the one that counts, and the preparation depot decides how far you must travel. Some people who type “assayers near me” want a jeweller’s purity test, which is the last row and a separate service from ore assay. If you are testing a jewellery piece or a scrap bar, ask for an assay office; if you hold rock from a claim, ask a geochemical lab.

How a gold assay works, step by step

Fire assay has barely changed in principle since ancient times. The lab mixes a weighed, finely ground sample with a flux of lead oxide and silica plus borax, soda ash and other reagents, then melts it above 1,000 degrees Celsius. The gold collects in a lead button. The button goes into a porous cupel in an oxidising furnace, which absorbs the lead oxide and leaves a small bead of precious metal. The bead is then weighed, or dissolved and read on an instrument, as ALS describes in its gold by fire assay method note.

Infographic

Gold fire assay in 5 steps

1. 1PrepareDry, crush, split and pulverise the sample, then weigh a 30 g or 50 g charge.
2. 2FuseMix the charge with a lead oxide flux and melt it above 1,000 degrees Celsius.
3. 3CollectThe gold gathers in a lead button; the glass slag is removed.
4. 4CupelThe button is heated in a bone-ash cupel, which absorbs the lead and leaves a doré bead.
5. 5MeasureWeigh the bead, or dissolve it and read it on an instrument, then check the controls.

The Nevada Bureau of Mines and Geology adds the details that explain the cost. The flux is chosen for the rock type, mainly silicate or carbonate; flour is added as a reducing agent so the lead oxide turns into lead metal; the molten charge is poured into a mould so the glass slag separates from the lead; and any silver in the bead is removed with nitric acid before the gold is weighed again. The US Geological Survey manual on fire assaying sets the typical charge at one assay ton, 29.167 g, because each milligram of gold from that charge equals one troy ounce in a short ton of ore (USGS Bulletin 1445). That is why 30 g, a round figure close to one assay ton, is a common charge; 50 g is a larger charge that some labs also offer.

Fire assay is accepted as the benchmark because it is a total decomposition that removes the rock and leaves only the precious metals to measure. ALS notes that this lets sensitive instruments report gold down to 1 part per billion on every sample, whatever the geology.

Gold assay methods compared

The finish decides how low and how high a lab can report, and it changes the price. The table uses ALS method codes because ALS publishes the ranges; other labs use their own codes for the same ideas.

Chart

Fire assay fee: 30 g against 50 g charge

Fee per sample in each lab’s own listing: Actlabs in C$ (February 2026), Paragon in $ (2025 schedule)

Ranges come from the ALS gold by fire assay page. The 30 g and 50 g choice matters less than most buyers expect. The chart shows what two labs charge for each; Actlabs adds that a 50 g charge may not give optimum recovery and that it may reduce charges to 15 g or less at its discretion when a fusion needs it.

Three notes on the other rows. First, screened metallics: SGS describes screening 500 g of sample to 106 microns, fire assaying the coarse fraction and a duplicate of the fine fraction, and reporting both fractions and the total (SGS fire assay brochure). Second, aqua regia: Bureau Veritas shows that a 0.5 g aqua regia portion and a 50 g fire assay agree well when gold is fine, but drift apart when coarse grains are present (Bureau Veritas, comparing fire assay and aqua regia). Third, handheld XRF: ALS states that gold cannot be reliably measured by portable XRF and that arsenic, tungsten and zinc can give false gold readings (ALS portable XRF technical note). A handheld gun can help log core, but it cannot replace a gold assay.

PhotonAssay, a newer method, measures 500 g of crushed rock without a fusion; Actlabs lists it at C$27.25 with a range of 0.03 to 350 ppm gold. Our companion pages cover fire assay for gold in more detail and assay services for every mineral, not just gold, including multi-element packages and mineralogy.

How to find and choose a gold assayer: 8 checks

Accreditation bodies publish directories, but no single list covers every gold assayer, so build a shortlist from three places: the accreditation bodies’ directories (next section), your state or provincial geological survey, and the sample-drop sites that the large labs publish. Then run the same eight checks on each lab.

1. Match the lab to the sample. Rock, soil and drill samples go to a geochemical lab; bars, doré and scrap go to a refinery or assay office.
2. Read the accreditation scope, not the logo. The scope must list gold by fire assay at the site that will do your work.
3. Ask for the current fee schedule in writing. Hazen quotes stay valid for 90 days and a copy must travel with your samples; compare preparation fees as well as the assay line.
4. Ask about small batches. Actlabs adds a C$250 setup charge to its 1A6 cyanide-based gold codes when a batch has fewer than 5 or 15 samples, depending on the code, so read the footnote of the code you want.
5. Ask for the turnaround date and the rush surcharge before you ship (see the turnaround section).
6. Ask what the lab keeps and returns. Paragon lists monthly storage for rejects and pulps and a charge for returning samples; keep the coarse reject until you have accepted the result.
7. Ask for the quality-control record. Blanks, duplicates and certified reference materials should be reported with your results. A lab that reports nothing about control samples cannot show its numbers are stable.
8. Send a check sample. Split a sample in two, send one half to this lab and one to a second lab, or insert a blank bag of barren rock. The 2002 Bureau of Land Management study of 65 North American labs found price a poor guide to accuracy, and it recorded blanks reported with gold and rich samples reported as none detected (ICMJ summary of the BLM study).

On location: the Bureau Veritas scope lists preparation sites in Whitehorse (Yukon), Timmins (Ontario), Sparks and Elko (Nevada), and Juneau and Fairbanks (Alaska), among others, and says physical preparation for accredited methods may happen at those sites or at the main lab. Hazen is in Golden, Colorado, and both Paragon and American Assay Laboratories list Sparks, Nevada. In the United Kingdom, the Sheffield Assay Office is one example of a hallmarking assay office that offers analysis. If none of these is close, a courier shipment to a main lab is normal practice; Paragon lists sample pick-up at $1.30 per highway mile.

ISO/IEC 17025: what accreditation proves and how to check it

ISO/IEC 17025 is the international standard for testing and calibration laboratories. Accreditation means an independent body has judged a lab’s impartiality and competence for named test methods; ILAC, the international cooperation of accreditation bodies, describes it as the independent evaluation of conformity assessment bodies against recognised standards. For you, the useful part is the scope: a lab can be accredited for one method and not for another.

Real scopes show what to look for. American Assay Laboratories in Sparks holds Inspection Accreditation Service certificate TL-536, effective 15 June 2026, with fire assay for gold, silver, platinum and palladium by ICP-OES finish and for gold by gravimetric finish listed under minerals, ores and geological materials (IAS certificate TL-536). The Standards Council of Canada scope for Bureau Veritas Commodities Canada, version dated 4 October 2024, valid to 7 October 2027, lists gold by lead-collection fire assay with ICP, atomic absorption and gravimetric finishes (SCC scope 15895). In Australia, the National Association of Testing Authorities lists gold by atomic absorption and fire assay in the scope of BV Minerals Perth (NATA scope). Actlabs says its quality system is registered to ISO/IEC 17025:2017 and accredited through the Standards Council of Canada, but its own office list marks some sites with ISO/IEC 17025 and others with ISO 9001 only, so accreditation is site by site.

To check a lab: ask for the certificate number, open the accreditation body’s own page or PDF (IAS, SCC, A2LA, ANAB, NATA or UKAS, depending on country), and confirm four things: the site address, the method (fire assay for gold), the sample type (ores and geological materials) and the expiry date. Accreditation does not guarantee a good result on your sample; it shows the lab’s method and controls have been audited. Banks, buyers and regulators often ask for accredited results, so decide early whether you need them.

Gold assay cost: published fees compared

Fee schedules published by the labs themselves are the best price evidence, because a quote by email cannot be checked later. All prices below are per sample and are quoted in the lab’s own currency, without conversion.

Chart

Actlabs fee for gold fire assay, by method

C$ per sample, Actlabs geochemistry schedule of services and fees, February 2026 (CAD)

Two things stand out. The assay line is only part of the bill: at Paragon a 2 kg rock sample costs $12.50 to prepare ($10.50 plus $1.00 per kg) and $21.40 to assay, $33.90 in all, while at Actlabs the same two steps total C$37.25. And the price of the method rises fast once you ask for coarse-gold protection: the Actlabs metallic screen costs almost four times the 30 g routine assay.

Extras that change the invoice: Hazen charges 100% more for priority service; Paragon charges 4% on credit-card payments and lists payment terms of 10 days; Hazen adds US$50 per job for a package that is hazardous but not labelled. Actlabs asks you to send two to three times the weight listed for each analysis so there is material for quality control. Prices change, so treat the table as a guide to relative cost and ask for a written quote.

How long a gold assay takes

Routine fire assay results at Hazen are normally reported within 15 to 20 business days, and the lab states it cannot guarantee a specific date. Priority service costs 100% more and typically delivers in about ten working days, again without a guarantee; it must be arranged before the samples are sent. Order confirmations are emailed within three business days of receipt, and it is worth reading that email closely because mistakes missed at that point can delay the report (Hazen fee schedule, July 2026).

Actlabs defines turnaround as the time from receiving a batch with clear identification and instructions until results are reported, and says it varies with batch size, methods, workload and the time of year. Wet or badly labelled shipments slow it down, and a rush date should be agreed, with its surcharge, before you ship. Actlabs also offers a sample-tracking portal, so you can watch a batch move from reception to preparation to analysis. Hazen’s 15 to 20 business days works out to three to four weeks, a fair planning figure for a routine batch.

Sampling mistakes that spoil a good assay

A fire assay is accurate on the 30 g or 50 g that goes into the furnace. Whether that portion represents your ground is up to you. Gold often occurs as scattered coarse grains, and a small portion that catches one grain reads high while the next one reads zero. Bureau Veritas explains the effect: one grain of native gold weighs far more heavily in a 0.5 g portion than in a 50 g portion, and in a data set with coarse gold the aqua regia results scattered and the bias grew with grade.

• Send enough weight. Follow the lab’s guidance on minimum weight, and ask for the whole sample to be crushed and split rather than a scoop taken from the top.
• Do not over-grind before the lab does. Actlabs warns that grinding too fine can make gold plate out on the mill and be lost, and when it describes its metallic screen method.
• Use metallic screening for visible or patchy gold. A screen assays the whole coarse fraction instead of a few grams of it.
• Add control samples. Insert blanks and duplicates among your real samples; the calculator above shows what an extra 10% costs as an example.
• Label and seal bags. Keep a written record of who took, carried and shipped each bag, with dates. That chain of custody is what a buyer or regulator asks for.

Reading a gold assay result

Results arrive as ppm, g/t or ppb (1 ppm = 1 g/t = 1,000 ppb), or as troy ounces per short ton. One ounce per short ton is 34.29 g/t (31.1035 g per troy ounce divided by 0.9072 tonnes per short ton), so a result of 0.1 oz/ton is about 3.4 g/t.

Chart

Gold in one tonne of rock by grade (g/t)

US$ of contained gold per tonne at spot gold of US$4,037.98 per troy ounce (28 October 2026); gross in-ground value

The chart converts grade into the value of gold in a tonne of rock. Spot gold traded at US$4,037.98 per troy ounce at 04:57 GMT on 28 October 2026 (Investing.com, reported by FinanceFeeds), which makes each g/t worth about US$129.82 per tonne of contained gold. That is gross, in-ground value only. What a miner can sell depends on recovery in the mill, mining and processing costs, the cut-off grade (the lowest grade worth mining) and royalties. A single assay of one grab sample says nothing about a deposit; it tells you the lab found gold in that bag, which is a reason to sample the ground systematically. The companion post on mining prospecting for gold covers deposit types and signs to sample, and active gold mines in the USA shows grades and ounces at operating mines for comparison.

Prospectors and small miners: permission, safety and next steps

Before you collect any sample, confirm you have the right to be on the ground and to take material from it. Land can be private, a mining claim held by someone else, or protected; rules differ by state and country, and our guide to gold panning laws in California is one example of how local they are. Use a licence or permit where one is required. Never use mercury to recover gold; it poisons you and the water downstream. Fire assay is not a kitchen job either: it uses furnaces above 1,000 degrees Celsius and lead-based fluxes, so send samples to a lab.

A sensible order of work for a small project: sample the ground in a grid or along a line, send a first batch with blanks and duplicates, plot the results on a map, then decide where to sample more. Satellite imagery can help before the first bag is filled, by screening ground for iron-oxide stains, clay alteration and structures so you sample where the signs are. Farmonaut turns a KML, KMZ or polygon boundary into satellite-derived exploration targets for early screening; the targets sit ahead of any resource estimate and need ground sampling and assay to test them. See satellite-based mineral detection, or send your boundary through the mining quote form.

▶ Owning a gold claim is not owning the land: how to buy a gold claim safely and check the ground first. · 3:19

Frequently asked questions

What does a gold assayer do?

A gold assayer prepares samples, runs fire assay or another method, checks the work against blanks and reference materials, and reports the gold content. At a mine that number guides grade control and processing; at a commercial lab it supports exploration decisions and sales.

How much does a gold assay cost?

A 30 g fire assay for gold was listed at C$23.00 at Actlabs (February 2026) and $21.40 at Paragon (2025 schedule). Hazen (July 2026) lists a gold fire assay with AA finish at US$55 but does not state the charge weight. Add sample preparation, which was C$14.25 at Actlabs and US$30 at Hazen per rock sample in the same schedules, plus shipping and any rush fee.

How do I find a gold assayer near me?

Start with the directories of accreditation bodies such as IAS, SCC, A2LA, ANAB, NATA and UKAS, then check which labs have a fire assay for gold in their scope and where their preparation sites are. Ask your state or provincial geological survey for a local referral, and compare written fee schedules from two or three labs.

What is the difference between an assay lab and an assay office?

An assay lab measures the gold in ores, concentrates and metals for mining clients. An assay office, such as the hallmarking offices in the United Kingdom, tests and marks the purity of jewellery and articles, and some also run analytical services.

Is ISO/IEC 17025 accreditation required?

Whether you need it depends on who will use the result. Banks, buyers and regulators often want accredited results, so ask them before you choose a lab. Check that the scope lists fire assay for gold at the site that will run your samples.

How long does a gold assay take?

Hazen reports routine results in 15 to 20 business days and about ten working days for priority work at double the fee (July 2026 schedule). Actlabs says turnaround varies with batch size and workload and quotes a date and surcharge for rush jobs.

Can a handheld XRF analyser measure gold?

No. ALS says gold cannot be reliably measured by portable XRF, and arsenic, tungsten and zinc can give false gold readings. Use it for screening other elements and send gold samples for fire assay.

How much sample should I send?

Ask the lab. Actlabs asks for two to three times the weight listed for each analysis so there is material for quality control, and routine rock preparation at Actlabs handles up to 7 kg per sample. Send a representative split, not a handful from the top of a bag.

Why do two labs give different gold results on the same rock?

Usually because the sample portions differ. Coarse gold makes small portions unreliable, and aqua regia and fire assay measure different things. Ask both labs for their method codes, sample weights and control results, and consider a screened metallics assay on a larger split.

Do assayers also test gold bars and jewellery?

Refineries and assay offices do. Bullion assay uses its own methods; Hazen lists a bullion gold assay at US$70, and The Perth Mint refinery says it meets LBMA technical requirements for assay capability.

What does a mine assayer need to qualify?

Requirements vary by employer. The Nevada Division of Minerals career sheet describes the assayer role as requiring a high school diploma and six months of fire assay and sample preparation experience, with written and hands-on tests.