How We Check

No single test proves a metal, so we combine several on the bench and require them to agree. Which ones we run depends on the item and its form; the record always shows exactly which were performed. Our standard non-destructive battery is visual inspection, weight, dimensions, magnet, conductivity (Sigma) and XRF composition, compared against known-good reference pieces.

Verification is based on non-destructive testing only. Surface composition, conductivity, magnetism, dimensions, weight and visual inspection are checked — internal adulteration cannot be fully excluded without advanced testing. We're most cautious on large gold bars, sealed assay-carded items and pieces whose edges or full depth can't be probed. A Metal Stack record indicates an item is consistent with the stated metal — it is not a guarantee of authenticity, a statement of legal fineness, or a substitute for an Assay Office hallmark.

Green · Verified

Visual, weight, dimensions, magnet, Sigma and XRF all agree.

Amber · Inconclusive

One minor inconsistency, an unusual or heavily-worn item, no reliable dimensions, or a Sigma/XRF mismatch — don’t buy at full confidence.

Red · Not consistent

Wrong weight or dimensions, magnetic attraction, a Sigma fail, XRF inconsistency, or casting/plating/serial problems.

Visual

Edges and reeding, fonts, mint marks, surface texture, casting signs and seams, plating wear, serials and assay packaging — examined under a loupe or microscope, plus UV. Often the most telling test of all.

Weight

Weighed to 0.01 g on a calibrated scale, checked daily against calibration weights. The exact figure and tolerance go on the card and record.

Dimensions

Diameter and thickness (coins) or length/width/thickness (bars) measured with callipers/micrometer against official specs — a lot of convincing fakes fail here.

Magnet

A quick screen: precious metals are non-magnetic, so strong attraction is an immediate fail. Useful, but never the whole story.

Conductivity

A Sigma Metalytics meter reads conductivity through the piece at multiple locations — a main test, and the one that catches matched-density cores such as tungsten under gold (probe depth matters on bars).

Composition

XRF reads the alloy and fineness from several angles — front, back and accessible edges. Excellent on the surface; we never let it override contradictory physical evidence.

Then it's carded, QR-linked and sealed

Each verified item ships with a printed verification card carrying its item number, weight, analysis result and QR code — plus a tamper-evident hologram that shows a clear VOID pattern if it's lifted or peeled. The QR resolves to the item's permanent record on this register.

⛓ Recorded, hashed, and anchored to Bitcoin

Every record gets a SHA-256 fingerprint you can recompute yourself from the published data — and each day the whole register is timestamped onto the Bitcoin blockchain (via OpenTimestamps, the same cryptography Bitcoin runs on), so its history can't be forged or backdated, by us or anyone. No tokens, no wallet — just proof. See the live proof.