Gübelin Rating for Colored Gemstones

Gübelin Rating for Colored Gemstones

“The more you know about colored gems, the more you value them…” very rightly put by Raphael Gübelin, President of the House of Gübelin. Gemstones, regardless of the purpose you are buying or selling them, should not be anything less than authentic. Yet, buying or trading gemstones is anything but easy and requires a certain amount of quality assurance.  The benefits begin right from the orientation and transparency, and comparability— all three offered through Gübelin rating.

The story behind Gübelin Rating

The Gübelin Gem Lab was established in 1923 to research and evaluate the authenticity of gemstones used only for Gübelin’s jewelry as a private gemological laboratory. The sole purpose behind Gübelin Gem Lab was to keep the genuineness and authenticity of Gübelin’s jewelry intact. Ever since then, it has grown to become one of the most reputed and esteemed institutions of its kind.

Using state-of-the-art equipment and technology to assess gemstones. The Gemological reports are trusted and respected by most royal families, gem traders, auction houses, gem collectors, and jewelers.

Equivalent to the four Cs (cut, clarity, color, and carat) of diamond rating Gübelin Gemstone Rating was created. It examines and assesses colored gemstones based on three factors- quality, rarity, and salience.

Parameters, Ratings & Domains 

The Gübelin Gemstone Rating contributes to the rarity, attractiveness, and beauty of the high-value colored gemstones. Non-synthetic, transparent, natural gemstones that are either polished or faceted qualify for the rating system. Other treatments like clarity enhancement and traditional heating are also accepted and rated. The following types of gemstones are mostly rated at the lab-

• Ruby
• Emerald
• Sapphire (also fancy colored sapphires)
• Padparadscha sapphire
• Paraiba tourmaline and Rubellite
• Spinel (red-pink)
• Alexandrite and chrysoberyl
• Aquamarine, morganite, and heliodor
• Demantoid, tsavorite, and mandarin garnet
• Tanzanite
• Imperial, red-pink topaz 

The Gübelin Gemstone Rating comprises three domains: quality, rarity, and salience.

• Quality- it covers the visual aspects and characteristics of the colored gemstone. This includes the color, tone, saturation and homogeneity, transparency, cut, clarity, and brilliance of the gemstone.

• Rarity- speaks for itself. It assesses the relative availability of colored gemstones in the market. Also, if any of its variety exists, along with size. Signs of treatment (presence, absence, and severity) are also checked under rarity.

• Salience- This factor assesses a colored gemstone beyond its physical exceptionality. It examines and rules out whether a gemstone is worthy enough to stand out or not.

The above features are examined, assessed, and scored based on overall rating on a scale of 75 to 100 Gübelin Points.

• 5-100- exceptional
• 0-97.4- outstanding
• 5-94.9- excellent
• 0-92.4- superior
• 0-89.9- fine
• 0-84.9- good
• 0-79.9- fair

Since the Gübelin Gemstone Rating system covers only the crème de la crème of the colored gemstone realm, they are scored from 75 to 100. Cheap gemstones, commercial quality, rough, opaque, translucent gemstones stand no chance to qualify for assessment. The range of points is scaled 75 and above and scored out of 100 since they are all high-end colored gemstones.

Procedure

With the help of state-of-the-art techniques, procedures, and standards, the simple and effective rating and assessment are carried out by experienced and trained experts. There are certain domains and parameters that evolve over time and are, therefore, reflected in the rating of a gemstone. The commercial value and Gübelin Gemstone Rating could also differ slightly.

The Rarest of the Rare

Speaking of exquisite gems, Maison Mirath’s colored gemstones collection— the Aura and Sabulosity have stellar written all over them. Excellent craftsmanship is an understatement with delicate yet majestic one-of-a-kind jewelry pieces encrusted with rare gemstones.

All in all, Gübelin Gemstone Rating helps in stating the factual quality of the colored gemstone. Prices may or may not vary, but in the end, it is the peace of mind of the buyer or the seller that settles after seeing the rating.