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Gübelin Points, GRS Platinum Awards and Other Premium Laboratory Distinctions

By the Byrex Gems team, Toronto · Published 25 September 2026

Gübelin Points, GRS Platinum awards, SSEF appendices and Provenance Books, Lotus Royal Gem comments: what each premium laboratory distinction means, who decides it, and its limits.

A standard laboratory report says what a stone is, how it has been treated and, sometimes, where it came from. At the top of the market, several laboratories also issue something extra: a score, an award, an appendix or a bound book reserved for exceptional stones. These distinctions are often mentioned in auction catalogues and dealer listings, and their names are easily confused. This article explains, from the laboratories' own descriptions, what each distinction is, who decides it and what it does and does not tell you.

Gübelin Gemstone Rating and Gübelin Points

Gübelin Gem Lab of Lucerne introduced the Gübelin Gemstone Rating in November 2020. It expresses a coloured stone's standing as a number of Gübelin Points, an idea Gübelin compared to the way wine is rated (National Jeweler). The Financial Times, as republished by Swissinfo, reported that development began in 2018 and drew on a database of more than 28,000 gems (Swissinfo).

The rating deliberately covers only the upper end of the market. Scores run from 75 to 100, and a stone must reach at least 75 points to receive a Rating Document. Gübelin's current bands are (Gübelin Gem Lab):

95–100
Category: Exceptional

90–94.9
Category: Outstanding

85–89.9
Category: Excellent

80–84.9
Category: Superior

75–79.9
Category: Fine

At launch, the scale was divided into seven narrower bands with different names, running from Fair to Exceptional. Older documents may therefore use different category names for the same score.

The score combines three components:

  • Quality, the main factor: colour (hue, depth, saturation and evenness), clarity, transparency, cut and brilliance.
  • Rarity: the type of gem, its weight and its treatment status. Gübelin states that country of origin is not part of the rating.
  • Salience: the qualities that make a stone stand out from others of its kind.

Eligible stones are natural and transparent. They include ruby, blue and fancy sapphire, padparadscha, emerald, spinel, alexandrite, cat's-eye chrysoberyl, Paraíba tourmaline, rubellite, aquamarine, morganite, heliodor, demantoid, tsavorite, mandarin garnet, tanzanite, imperial topaz and peridot. Traditionally heated stones can qualify. The rating is included for most stones submitted for a Gübelin Gemmological Report. It is also sold on its own, but a standalone rating relies on microscopic examination only and is not equivalent to a full report. Gübelin says plainly that the rating is not a valuation, that it should not be used to draw direct conclusions about price, and that it involves some subjectivity (Gübelin Gem Lab).

Other Gübelin distinctions

  • Gemmological Portrait: a bespoke book with dedicated photography and a written account of the stone. A stone qualifies only with the unanimous approval of the laboratory's experienced gemmologists, and no more than four copies are made for each stone (Gübelin).
  • Gemmological Profile and Profile Plus: documents that add background on the gem type, inclusion photographs and analytical detail to the report. The leather-bound Profile Plus is reserved for exceptional stones (Gübelin).
  • Trade colour terms: Gübelin uses pigeon blood red and royal blue under definitions harmonised with SSEF in November 2015, which apply only to stones without colour or clarity modification (IDEX). From 1 January 2027 it will add "cornflower blue" for untreated blue sapphires of any origin with a saturated, light-to-moderate-toned blue (Gübelin).
  • Provenance Proof and the Emerald Paternity Test: Provenance Proof is an independent subsidiary of the Gübelin Gem Lab that develops traceability tools, including a blockchain logbook (Gübelin). Its Emerald Paternity Test, presented in 2017, tags rough emeralds at the mine with DNA-based nanoparticles smaller than 100 nanometres. The tags survive cutting and polishing, and the test was trialled with Gemfields at the Kagem mine in Zambia (National Jeweler). It proves which mine a stone came from. It does not grade the stone.

The GRS Platinum Rarity Gemstone Award

GRS GemResearch Swisslab offers a Platinum Rarity Gemstone Award for exceptional gemstones and jewellery. The award is a three-fold premium report that classifies the stone as either "Important" or "Magnificent". It comes with an appendix describing the stone's rarity, an enlarged high-resolution photograph, a 360-degree augmented-reality video and a unique award number. GRS decides eligibility at its own discretion. It compares the stone against its own data from more than 20 years and auction results collected over more than 30 years (GRS). A further tier, the Platinum Rarity Gemstone Award Book, is a hardbound book of 40 to 50 pages on the stone's history and geology. GRS currently limits it to rubies and sapphires from Burma (Myanmar) and Sri Lanka and emeralds from Colombia (GRS).

GRS does not publish its criteria as a points scale or a public list of awarded stones. The words "GRS Platinum" in a listing are therefore a claim to check. Ask for the report and award numbers and verify them with GRS.

GRS-type colour terms

When a GRS report says "GRS type", it refers to one of the laboratory's colour designations, not to diamond type. The best known are "pigeon's blood" for ruby and "royal blue" for sapphire. GRS says these first appeared in an auction catalogue in June 1998, registered them as trademarks in 2015, and in 2017 divided them into intense to vivid, vivid, and vivid to deep. Emeralds in the equivalent green bands receive an "Old Mine/Muzo Green" appendix (GRS colours).

A GRS pigeon's blood ruby must be vivid red with medium to strong fluorescence under 365 nm ultraviolet light and high chromium relative to iron. Heated stones and stones of any origin can qualify. The term is refused for beryllium-treated, lead-glass-filled, surface-diffused and synthetic stones and for GRS residue grades H(c) and H(d) (GRS). Colour zoning, windowing or weak brilliance can also keep a stone from the designation. GRS additionally tests orange, yellow and padparadscha sapphires for colour stability and records the result as a numbered type (GRS).

SSEF appendix letters, Premium Appendix and Provenance Book

SSEF of Basel attaches an appendix letter to the report of a gem, pearl or jewel that passes its strict quality criteria and that it considers exceptional. Owners of such items can order the SSEF Premium Appendix, a handmade leather folio holding the report, the appendix letter and a high-resolution photograph, for an extra fee of CHF 2,500 (SSEF). SSEF uses "pigeon blood red" and "royal blue" only for untreated stones that meet its colour, fluorescence (for ruby), clarity and homogeneity criteria (SSEF).

For the most important stones SSEF produces a Provenance Book. One recent example is the 55.22-carat Estrela de Fura ruby from Mozambique. SSEF found it unheated and issued a Provenance Book after testing in February 2023. The ruby sold at Sotheby's New York on 8 June 2023 for US$34.8 million, a record for a ruby (SSEF). SSEF's GemTrack service, launched in 2019, documents that a cut stone came from a particular rough crystal. It is issued only alongside an SSEF report (SSEF).

GIA: diamond type and exceptional grades

GIA has no award tier, but for diamonds it can add a finding of great interest to collectors: the diamond type. GIA offers diamond type analysis as a supplemental service using infrared spectroscopy (GIA 4Cs). Type IIa diamonds contain no measurable nitrogen or boron. Type Ia stones make up more than 95% of natural diamonds (G&G, Summer 2009). Record pinks show how the type is presented. The 59.60-carat Pink Star, graded Fancy Vivid Pink, Internally Flawless and type IIa, sold at Sotheby's Hong Kong in April 2017 for US$71.2 million (National Jeweler). The 11.15-carat Williamson Pink Star, also Fancy Vivid Pink, Internally Flawless and type IIa, sold at Sotheby's Hong Kong in October 2022 for US$57.7 million (Sotheby's).

Lotus, AGL and C. Dunaigre

  • Lotus Gemology (Bangkok) offers a one-page "Gem of Distinction" comment for fine gems and a three-page "Royal Gem" comment reserved for the very top stones, both added to hardcover reports (Lotus price list). Its hardcover reports use gold covers for untreated stones (Lotus).
  • AGL (New York) calls its main report the Prestige Report. At its full-grading level it grades colour, clarity and cutting and sums them up in a Total Quality Integration Rating (AGL).
  • C. Dunaigre (CDC) may issue an addendum highlighting an exceptional gemstone's attributes, at the gemmologist's discretion and at no charge (C. Dunaigre).

Summary

Gübelin Gemstone Rating (Gübelin Points)
Laboratory: Gübelin
What it is: Score of 75–100 for quality, rarity and salience
Who qualifies: Natural stones of eligible species scoring 75 or more

Gemmological Portrait
Laboratory: Gübelin
What it is: Bespoke book, maximum four copies
Who qualifies: Stones approved unanimously by Gübelin gemmologists

Platinum Rarity Gemstone Award
Laboratory: GRS
What it is: Premium report graded "Important" or "Magnificent"
Who qualifies: At GRS's discretion

Platinum Award Book
Laboratory: GRS
What it is: 40–50 page hardbound book
Who qualifies: Burma and Sri Lanka ruby and sapphire; Colombian emerald

Appendix letter / Premium Appendix
Laboratory: SSEF
What it is: Letter noting exceptional quality; leather folio
Who qualifies: Items SSEF considers exceptional

Provenance Book
Laboratory: SSEF
What it is: Book on a major stone
Who qualifies: Exceptional gems

Royal Gem / Gem of Distinction
Laboratory: Lotus
What it is: Additional comment pages
Who qualifies: Top and fine gems respectively

Prestige Report (full grading)
Laboratory: AGL
What it is: Graded report with a summary rating
Who qualifies: On request

Why these distinctions matter, and their limits

For collectors, premium documents do two things. They confirm that an independent laboratory, having seen many comparable stones, judged this one exceptional. They also give buyers and auction houses a shared shorthand. That is why appendices, colour terms and awards appear so often in catalogue descriptions of important stones. Distinctions still rest on the basic findings underneath: identity, treatment and origin. A premium folio adds nothing if those findings are unfavourable. Criteria differ between laboratories, and at Gübelin even the category names have changed since launch. None of these laboratories presents its distinction as a price. Treat them as expert opinions that support a valuation, not replace one, and always verify the underlying report number with the issuing laboratory.

To discuss a stone with a premium laboratory document, or any stone with a laboratory report, email info@byrex.com or send a WhatsApp message to +1 (437) 450-3786.

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