Coin Grading & Certification

Frequently asked

Numismatics questions, answered.

What grading scale does Xene use for coins?

The 70-point Sheldon scale (Poor-1 through Mint State 70) for milled and modern coinage. Hammered and ancient coins receive a separate descriptive grade plus authenticity certification, in line with RNS conventions. For ancient coins the grade is expressed in the adjectival system (Poor through Uncirculated) accompanied by a written condition report noting strike, wear, and known provenance.

Are coins X-rayed before grading?

All coins above Standard tier receive non-destructive X-Ray Fluorescence (XRF) analysis to confirm metallic composition. Specific gravity is measured for bullion-grade material. Tier and discipline determine the precise battery of tests. XRF results are recorded numerically and appended to the registry entry; any composition falling outside the expected alloy tolerance is flagged in the certificate notes.

Can I submit raw coins with potential mint errors?

Yes. Mint errors (doubled dies, off-centre strikes, planchet flaws, repunched mintmarks, brockages, capped-die strikes) are catalogued and certified with the variety attribution noted on the certificate. Where the error is significant, we reference the Cherrypickers' Guide, Fivaz-Stanton, or Overton as appropriate, and cross-check against known population data.

Will cleaning reduce the grade?

Cleaning destroys mint lustre and is detected under stereo microscope and raking light. Cleaned coins receive a 'Details' designation rather than a numeric grade, with the form of cleaning specified on the certificate (hairlines, whizzing, polishing, chemical stripping, dipping). Artificial retoning applied to mask cleaning is also reported under the 'Details' category.

What exactly counts as a 'Details' designation?

Any post-mint alteration that materially affects the coin's surface or originality: cleaning of any kind (mechanical or chemical), artificial toning, tooling, plugging, re-engraving, planchet alteration, physical damage, and significant repairs. A coin can receive a Details grade while still being genuine and desirable — the certificate discloses the specifics so the market can price accordingly.

Do you cross-certify slabs from PCGS or NGC?

Yes, under our cross-certification protocol. The coin is removed from its existing holder in our presence, examined fresh, regraded against Xene standards and placed in the Xene holder. The original holder is returned to you. The previous certification service is noted on the Xene certificate for provenance continuity.

What provenance documentation do you accept?

We accept and record auction catalogues, estate inventories, prior third-party certificates (PCGS, NGC, ANACS, ICG), correspondence, and published references naming the specific coin. Provenance is recorded in the registry entry and, for Specialist and Private Office submissions, appended in full to the certificate. A clear chain of ownership strengthens both the historical record and any insurance claim.

What is your policy on conservation and restoration?

Xene does not perform cleaning or conservation. We refer to approved conservators only for Specialist-tier and Private Office submissions where the HoD deems intervention appropriate before grading. Any conservation work is fully disclosed on the certificate and registry entry. We do not certify coins dispatched directly from a conservator without a fresh independent examination by our own graders.

How is insurance handled during transit?

Xene works with a designated insured courier network. Each submission is assigned a declared value at receipt; transit insurance at that value is included in the service fee for Standard tier and above. Economy-tier submissions require the client to arrange their own transit cover. Full packing instructions and courier details are provided upon confirmation of submission.

Do you publish registry and population reports?

Yes. The Xene registry is publicly searchable by reference number, item description, and grade. Population reports — showing the number of examples of a given coin certified by Xene at each grade point — are updated in real time after each encapsulation. Population data supports rarity assessment and underpins insurance and auction valuations.

What is the difference between a die marriage and a variety?

A variety is any deviation from the intended design: a repunched mintmark, an overdated obverse, a doubled die, or an altered legend. A die marriage is the specific pairing of a named obverse die with a named reverse die — the primary unit of attribution for early American coinage in the Overton reference. Xene certifies both variety and die-marriage attributions, citing the relevant reference on the certificate.

Can I submit a partial collection, or re-holder previously certified Xene coins?

Partial submissions of any size are accepted — there is no minimum for Standard tier and above. Re-holdering of Xene-certified coins (where a holder has been damaged or a new registry format issued) is accepted at a reduced administration fee; the coin is re-examined and the original grade confirmed or, if warranted, revised.

Recent case notes

From the numismatics bench.