GRS Premium is a report designation issued by GemResearch Swisslab (GRS), the Swiss gemmological laboratory founded by Dr. Adolf Peretti, applied to high-quality coloured gemstones that satisfy elevated internal benchmarks for colour, clarity, and — where determinable — geographic origin, but do not reach the laboratory's uppermost Platinum threshold. Within the structured tier system that GRS has developed for ruby, sapphire, and other commercially significant species, the Premium designation occupies a clearly defined second rank, signalling to buyers and sellers that the stone has been assessed against rigorous criteria and found to be of notably superior quality without attaining the rarest grade.

Structure of the GRS Tier System

GRS organises its quality opinions into a hierarchy that, in descending order, runs from Platinum through Premium to standard report grades. The Platinum designation is reserved for stones that GRS considers to represent the finest known examples of their kind — typically gems displaying the laboratory's top colour calls (such as pigeon blood for Burmese ruby or royal blue for sapphire) in combination with exceptional clarity and transparency. Premium sits immediately below this level, capturing stones of genuinely high quality that meet elevated internal criteria but exhibit some characteristic — whether a minor clarity feature, a slight deviation from the ideal colour saturation, or a combination of factors — that places them outside the Platinum band.

It is important to understand that these tier designations are proprietary quality opinions specific to GRS and are not standardised across the gemmological laboratory industry. Other major laboratories — including Gübelin, SSEF, and Lotus Gemology — issue their own report formats and quality descriptors, which are not directly equivalent to GRS tier nomenclature.

Colour Designations and the Premium Report

A GRS Premium report may carry one of the laboratory's trademarked colour descriptors when the stone's colour satisfies the relevant criteria. For ruby, this most commonly means the pigeon blood designation, GRS's term for a vivid, slightly fluorescent red with a characteristic hue and saturation profile associated historically with Burmese production. For blue sapphire, the descriptor royal blue may appear. The presence of such a colour call on a Premium report — as opposed to a Platinum report — indicates that the colour criterion has been met but that other quality factors have influenced the overall tier assignment. In the trade, a Premium report bearing a top colour descriptor is nonetheless considered a strong commercial credential, particularly for stones in the mid-to-upper price range where Platinum-graded material is scarce.

Market Recognition and Commercial Significance

GRS Premium reports are widely accepted in the international coloured-gemstone trade, particularly in the major trading centres of Bangkok, Hong Kong, and Geneva, where GRS has established a strong presence. Auction houses and dealers routinely reference the GRS tier designation in lot descriptions, and the Premium grade is understood by informed buyers to represent a meaningful quality statement rather than a marketing convenience. Stones accompanied by GRS Premium reports typically command a price premium over comparable material carrying only a standard GRS report, though they are generally priced below equivalent stones holding GRS Platinum documentation, all other factors being equal.

Buyers should note that the tier designation reflects GRS's assessment at the time of examination and is subject to the laboratory's evolving internal standards. As with all laboratory reports, the opinion is not a guarantee of value and should be considered alongside independent gemmological evaluation, market comparables, and the stone's physical characteristics.

Further Reading

• GemResearch Swisslab (GRS) — gemresearch.ch
• Gems & Gemology — gia.edu