How to Verify Gold Purity Before Depositing to a Gold IRA

Verifying gold purity before depositing to a Gold IRA is a three-layer process: the metal must meet IRS fineness standards under IRC section 408(m)(3), it must come from a refiner or mint on the depository’s approved list, and the physical inventory must pass an intake assay (X-ray fluorescence reading, weight check, and serial number match) at the depository before the custodian posts it to the account. The sequence below walks through the IRS fineness rules, the assay technologies depositories actually use (XRF, specific gravity, ultrasonic, electromagnetic conductivity), what a buyer can check at home before shipment, what the depository checks on intake, and the typical timeline from dealer purchase to confirmed IRA deposit. None of this is tax or financial advice. Consult your tax advisor for your specific situation.

The IRS Fineness Rules: The Floor Every Bar or Coin Must Clear

The IRS sets the minimum purity standards for precious metals held inside an Individual Retirement Account in Internal Revenue Code section 408(m)(3). Anything below the floor is not IRA-eligible and the depository will not accept it for the account. Reading the statutory text directly is the safest reference because IRA dealer marketing copy sometimes simplifies away the corner cases.

The statute also requires the metal to be produced by a refiner, assayer, or manufacturer that holds accreditation from one of the named bodies: NYMEX, COMEX, NYSE/LIFFE, LME, LBMA, LPPM, TOCOM, or ISO 9000, or be a coin produced under the authority of any United States or foreign government. In practice the depository’s internal approved list is narrower than the statute, because the depository takes on the liability for what it admits. A refiner that is technically accredited but not on the depository’s list will be rejected at intake.

Two purity nuances come up most often in conversations between buyers and dealers:

• The Gold Eagle exception is a numbered statutory carve-out, not a precedent. The Gold Eagle is allowed at 0.9167 because Congress named it. The South African Krugerrand has the same 0.9167 fineness and is not IRA-eligible because it is not named in the statute. Fineness alone does not determine eligibility.
• Coin proof variants are eligible only if they meet the same fineness and accreditation rules. Some proof, burnished, or numismatic variants of IRA-eligible coins are accepted; others are not, depending on whether the variant is documented as a coin under government authority or repositioned as a collectible. Confirm with the dealer in writing whether a specific variant is on the depository’s approved list before the purchase ships.

The Refiner and Mint Approved Lists: The Source Filter

Every IRA depository maintains an approved list of refiners and mints whose product it will admit on intake. The two industry references most depositories rely on are the LBMA Good Delivery list and the COMEX Approved Brands list, plus the named sovereign mints.

The buyer should ask the dealer two written questions before the purchase ships:

1. Which refiner or mint produced this specific inventory line?
2. Is that refiner on the destination depository’s approved list (not just on LBMA Good Delivery)?

A dealer that cannot answer either question quickly and in writing is not ready to ship into an IRA. The refiner identity is on the bar itself (stamped hallmark) and on the certificate of assay that travels with the bar. Sovereign coins carry the mint identity in the surface design and on the edge or rim.

Assay Technologies Used by Depositories

The depository intake assay is non-destructive and runs on every bar (with sampling on large coin lots). The four technologies in standard use are X-ray fluorescence, weight verification, specific gravity, and electromagnetic conductivity. Each technology answers a different question; depositories typically pair two or more.

X-ray fluorescence (XRF)

A handheld or benchtop XRF analyzer directs a low-energy X-ray beam at the bar surface. The X-ray excites inner-shell electrons of the metal atoms, and the secondary X-rays emitted on relaxation carry element-specific energies. The detector reads the full spectrum and reports the percentage composition by element. Modern handheld units report in under 60 seconds with accuracy of roughly 0.1 percent on the analyzed surface layer.

The limitation is depth: XRF reads the top 10 to 30 microns of the surface. A bar with a thin gold cladding over a tungsten core can pass XRF on the surface if the cladding is thicker than the read depth. This is why depositories pair XRF with a density or thickness check. XRF on its own is sufficient for sovereign-mint coins (where the manufacturing pathway makes a clad counterfeit far harder to produce undetected) and for sealed certified bars from LBMA-listed refiners.

Weight verification on a calibrated scale

Every bar and coin has a published weight specification with a tight tolerance. A 1 troy ounce gold coin weighs 31.103 grams. A 1 kilogram gold bar weighs 1000.000 grams. A calibrated precision scale measures the actual weight to 0.01 gram or finer. Counterfeit cores (tungsten, lead, copper, depleted uranium) have densities that differ from gold by enough to produce a noticeable weight discrepancy when the volume of the item is constrained by visible external dimensions.

Tungsten is the closest density match to gold and is the historical core material of concern. Even tungsten produces a small weight gap in a finished coin or bar because the cladding metal (gold) is denser than the substrate inclusions that the manufacturing process introduces. The weight check is a strong second filter behind XRF.

Specific gravity (density) test

The density test weighs the bar in air, then weighs it submerged in distilled water, and calculates density from the two readings (the volume of water displaced equals the volume of the bar, by Archimedes’ principle). Pure gold’s density is 19.32 grams per cubic centimeter. The closest counterfeit substrate, tungsten, sits at 19.25 grams per cubic centimeter. Most other potential cores (lead at 11.34, copper at 8.96, silver at 10.49) are far below gold and stand out immediately.

The density test catches counterfeits that defeat surface XRF. It is slower than XRF (a few minutes versus seconds) so depositories use it on a sample of each shipment or on any item flagged by XRF or weight as borderline. A bar that matches surface XRF, matches weight specification, and matches density curve is highly likely to be genuine.

Electromagnetic conductivity (Sigma-style verification)

Some depositories also run an electromagnetic conductivity check using a Sigma Metalytics Precious Metals Verifier or an equivalent device. The instrument passes a low-frequency magnetic field through the full thickness of the item and measures the conductivity response. Pure gold has a specific conductivity signature that differs measurably from tungsten, lead, and base metals across the full volume. The verifier is non-destructive, fast (about 5 seconds per coin), and reads through the full item rather than the surface layer.

The Sigma verifier is the same instrument many serious retail dealers run on incoming inventory before they list it for sale. A buyer who wants pre-deposit assurance at home (without the lab-grade equipment of the depository) can buy or rent one to spot-check sovereign coins before sending them on.

Ultrasonic thickness gauge

An ultrasonic thickness gauge sends a high-frequency sound pulse through the bar and reads the time for the echo to return from the opposite face. The pulse travel time at a known sound velocity for gold gives a thickness reading. The reading is compared against the published bar thickness. A bar with an internal density discontinuity (a tungsten core inside a gold shell, for example) produces a secondary echo from the internal interface, which the gauge flags. Ultrasonic is used on larger bars (100 oz and kilobars) where the volume justifies the slower per-item read.

What a Buyer Can Verify at Home Before Shipment to the Depository

Some buyers want a pre-shipment check before the metal leaves the dealer or the buyer’s hands en route to the depository. The checks below are non-destructive and will not disqualify the metal at depository intake. Acid tests, scratch tests, and any procedure that marks or alters the surface should not be used on IRA-bound bullion. They will create cosmetic damage that may cause the depository to reject the item, even if the underlying gold is genuine.

For sealed bars in tamper-evident assay cards (a common format for small Valcambi, PAMP, and Argor-Heraeus bars in 1 oz, 10 oz, and kilobar formats), the recommended practice is to leave the assay card sealed and confirm the serial number against the certificate. The seal is the manufacturer’s documentary chain of custody; breaking it puts the burden of full re-assay on the buyer. The depository will accept the sealed card as evidence of refinery assay subject to its own intake check.

The Depository Intake Process Step-by-Step

Once the dealer ships, the destination depository runs a defined intake sequence. The exact form names vary by depository, but the structure is consistent across the major IRA-approved facilities.

1. Carrier delivery and chain-of-custody handover. The carrier delivers the sealed shipment to the depository’s secure receiving area. Depository staff log the carrier seal number, the package weight, and the carrier manifest, and confirm the chain-of-custody record matches the dealer’s shipping notice.
2. Document review. The depository checks the dealer’s shipping manifest against the IRA account on file: account number, custodian, depository sub-account, and inventory line items requested. Any mismatch is held aside and the custodian is contacted before the shipment is opened.
3. Package opening under camera. The depository opens the package under video surveillance. The internal packaging is inspected for tamper indicators (broken seals, evidence of substitution, weight changes against the carrier manifest).
4. Refiner approved-list check. Each item’s refinery or mint identity (visible hallmark, mint stamp, certificate of assay) is cross-checked against the depository’s approved list. Items from non-approved sources are set aside and returned to the dealer.
5. Weight verification on a calibrated scale. Each item is weighed to the published tolerance. A 1 oz gold coin must weigh 31.103 grams within the tolerance band; a 1 kilogram bar must weigh 1000.000 grams within the tolerance band. Discrepancies trigger additional assay.
6. XRF surface read. A handheld or benchtop XRF analyzer reads the surface composition of each bar (and a sample of each coin lot). The composition must match the stated fineness within the analytical tolerance of the instrument. Items flagged by XRF are set aside for density and ultrasonic follow-up.
7. Density or ultrasonic confirmation (sampled or as needed). For larger bars or any flagged item, the depository runs a density test or ultrasonic thickness gauge to confirm uniform composition through the full volume.
8. Serial number cross-check. Each bar’s serial number is recorded and matched to the certificate of assay. The serial then becomes part of the IRA’s segregated or commingled inventory ledger under the account.
9. Posting to the IRA account. Once all items pass the intake checks, the depository confirms receipt to the custodian, the custodian posts the inventory to the IRA account, and the buyer sees the inventory on the next custodian statement (typically within 1 to 3 business days of intake completion).

If any item fails any check, the depository holds it in a quarantine position and notifies the custodian. The standard procedure is for the custodian to return the item to the dealer at the dealer’s expense and for the dealer to either replace the inventory with a verified item or credit the IRA in cash. A written intake guarantee from the dealer covering this scenario should be obtained before the purchase ships.

Timeline Expectations: Dealer Purchase to Confirmed IRA Deposit

Most IRA inventory clears the dealer-to-depository pipeline in 5 to 15 business days under normal conditions. The table below breaks down the typical phase-by-phase timing.

Three factors lengthen the timeline beyond the typical band:

• Refinery production lead time. If the dealer does not hold the specific bar or coin in vault inventory at the time of the order, the dealer may need to order from the refinery. Production and delivery from the refiner add 5 to 30 business days depending on the refinery’s backlog and the specific format requested.
• Holiday weeks and high-volume periods. Year-end IRA funding deadlines (April 15 for prior-year contributions), end-of-year rollover surges, and gold price spikes can extend dealer and carrier timelines by several days.
• Item rejected at intake. A rejected item triggers a full return-and-replace cycle: 2 to 5 days carrier back to dealer, 1 to 5 days for the dealer to source replacement, and 2 to 5 days carrier back to depository. The IRA’s cash balance may be the holding position for the rejected segment until replacement clears.