A laboratory report is only as useful as the link between it and the article. The report may be genuine and its findings correct, and still describe a different bead or stone from the one in your hand. Matching is the step that closes that gap, and the report is designed to make it possible: every measurable property on the card is there so that you can compare it with what you have.
What to compare
Weight. Use a balance that reads to 0.01 g (jeweller's scales are inexpensive). For a Rudraksha, compare grams; for a gemstone, compare carats (grams × 5). A genuine match agrees to within a few hundredths.
Dimensions. A vernier calliper or a ruler with millimetre marks. Width and height for a Rudraksha; length, width and depth for a stone. A match agrees to a few tenths of a millimetre.
Photograph. The image on the card and in the online record. Compare the outline, the position of distinctive features, and — for Rudraksha — the pattern of grooves and surface bumps, the shape of the crown, any pits or holes. For a stone, the outline of the cut, the position of visible inclusions, any chip or natural.
Colour and shape description. Plain-language fields that should not contradict what you see.
Findings that you can observe. The mukhi count of a Rudraksha; the colour of a stone; the number of beads in a mala.
Tolerances
Weight. A Rudraksha absorbs oil and loses moisture; a difference of a few hundredths of a gram in either direction is normal, and a bead that was oiled after testing may be up by a tenth. A gemstone's weight does not change: a difference of more than 0.01–0.02 ct is a different stone (or the stone has been re-cut).
Dimensions. Do not change. A difference of more than a few tenths of a millimetre, allowing for the imprecision of a hand-held gauge, indicates a different article.
Photograph. Lighting and angle differ; features do not. If you cannot find the distinctive features of the photograph on the article, look harder, then doubt.
When the match fails
Small weight difference, dimensions and photograph match. Oil, moisture or a rounding difference. The article is almost certainly the one tested.
Dimensions differ. A different article. Contact the seller and the laboratory.
Photograph shows different features. A different article, however close the numbers.
Everything differs. The card was transferred from another item. The card may still be genuine — verify it — but it does not describe this article. How to spot a fake or altered certificate.
Matching a mala or bracelet
Total weight, bead count, bead size, and the guru bead's individual figures where reported. A strand cannot be matched bead by bead; the totals and any distinctive beads are the check.
Matching a set stone
The report should say whether the stone was weighed loose or estimated in its setting. A set stone's dimensions can be measured with care; its weight can only be estimated. The photograph and the inscription (for diamonds) carry more of the load.
Why it is worth the ten minutes
Transferring a genuine certificate from a good article to a lesser one is the one form of certificate fraud that no verification system catches, because the certificate is real. Matching is the only defence, and it is a strong one: a substitute article of identical weight to two decimal places and identical dimensions is very hard to find. Most transferred cards fail on the first measurement.
Frequently asked questions
I do not have a precision balance. Can I still match?
Dimensions with a ruler and the photograph will catch most substitutions. A jeweller will weigh an article for you in a moment.
The report gives weight in carats and my balance reads grams. What do I do?
Multiply grams by 5 to get carats, or divide carats by 5 to get grams.
The bead looks darker than the photograph. Is it a different bead?
Colour changes with oil, wear and lighting. Compare the surface features, not the shade.
Can a laboratory re-match an article for me?
Yes. Submitting the article with the card allows the laboratory to confirm against its register and photograph, and to issue a note or a fresh report.
My stone has been re-cut since the report. Does the report still apply?
The identity findings do; the weight and dimensions do not. A fresh report is advisable for resale.