How We Grade Rubies & Pink Sapphire - Greenland Ruby

The Greenland Ruby Grading Process

The Greenland Ruby grading process for rubies and pink sapphires is conducted at our offices in Thailand, where skilled graders with years of industry experience and expertise perform scrupulous evaluations at every step of the grading process.

The grading process consists of four stages in total, during which gems are classified by their dimensions and weight, clarity, and color, plus a final review.

Dimensions & Weight

Our rubies and pink sapphires are cut in free and calibrated sizes ranging from 0.8mm to 20mm. Shapes include: oval, round, pear, cushion, long cushion, heart and sugar loaf. All gems have a unique identification number and come with a Certificate of Origin. This number acts like the gem’s DNA, which allows them to be tracked and traced from mine-to-market, from rough to polished.

Rough sourced from primary hard rock deposits yield gems suitable for cabochons. This makes Greenland Ruby the first colored gemstone mining company to responsibly bring calibrated cabochons into the marketplace. 


Clarity of our rubies and pink sapphires is graded accordingly:

  • Transparent (T): Light penetrates the stone, fire and brilliance are present.
  • Translucent (TL): Light penetrates the stone, fire is absent.
  • Opaque (O): Light does not penetrate the stone.

Within each clarity, our gems are further categorized

  • A: No visible inclusions
  • B: Inclusions are visible on the side of the gem but cannot be seen from the top.
  • C: Inclusions are visible on the surface/top view of the gem.


The rubies and pink sapphires range in color from deep dark red, known and ‘Pidgeon Blood’ in the Gem Industry, to light and icy pink.

Final Review

The last and final step of the grading process includes a final review by an expert grader whose sole job is to oversee and double check all aspects of the initial grading process.

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