How to grade gemstones?

Not all precious gemstones (diamond, ruby, sapphire and emerald) are created equal. There are various gemstone grades that are assessed by cut, clarity, colour and carat

What are the different grades used for?

  • Historically, high-grade precious gemstones were traditionally owned by royalty members, the clergy and the elite. These days, anyone who is exceptionally affluent can own a high-grade stone, yet they are extremely rare and incredibly expensive.
  • Mid-grade precious gemstones are commonly found on the commercial market
  • Low-grade precious stones are kept for industrial use, such as diamond glass cutters and sapphire semi-conductors

What is the grading scale for gemstones and diamonds?


For coloured precious gemstones, the more vibrant the hue, tone and saturation the higher the value. Pure, strong and rich colours will grade higher. For diamonds in the D-to-Z range, the opposite is the case. A clear, colourless diamond signifies purity and rarity, and is therefore valued at a higher grade. 


Clarity is graded by the number of inclusions a gemstone contains. Inclusions are characterized as anything that interferes with the free passage of light. A precious stone with lots of inclusions will possess a duller transparency and luminosity, alongside a more fragile structure.  


Each precious gemstone is formed with its own character, be it natural or lab-grown. A skilled craftsman can perfectly cut the stone to accentuate its charisma, colour and brilliance. Stone cutting is a highly-skilled art and an expert cut is measured by perfect symmetry, proportions and polish. These factors ensure a gemstone’s facets interact with the light beautifully. 


Gemstone weight is measured in carats. Rarity means larger gemstones of the same quality are worth more per carat. One-carat emerald will appear larger than a one-carat diamond and sapphire because its density is lower.

Juvetti Use Only the Highest Graded Precious Stones

Just like natural stones, precious gemstones created through lab-cultured methods come in a varied quality, yet only the carefully hand-selected, superior stones make the cut for Juvetti. From vivid colour saturation to flawless facets, our gemstones boast all of the finest qualities and are 100% ethically made

Beautiful gems fit for the Crown Jewels, accessible to us all to cherish forever. 

Browse our selection of precious stone ethical jewellery here