Article · 10 min
Why choose a light-coloured sapphire for an engagement ring?
Why a light-coloured sapphire needs a closer look Why does colour matter so much when you choose a pale sapphire? Colour has the greatest…
Gemstones · Learning pillar
Gemstone Fundamentals & Quality
Coloured gemstones are judged mainly on colour, and colour has its own vocabulary. This pillar explains how gemstones are evaluated overall, then breaks down the three dimensions of colour — hue, tone and saturation — so you can describe and compare stones precisely. Read how gemstones are evaluated first, then the hue-tone-saturation guide. These fundamentals underpin every individual gemstone entry in the encyclopedia and every buying guide.
Guides in Gemstone Fundamentals & Quality
Buying guide · 7 min
Why do two rubies look so different? How to buy a ruby
Why colour matters most when you buy a ruby Why start with colour when you compare rubies? Because colour is the most significant factor…
Buying guide · 7 min
Why colour comes first: how to buy a sapphire
Why colour comes first when you buy a sapphire Why start with colour? Colour has the greatest influence on a sapphire’s value. In general,…
Article · 9 min
What makes one stone better? How to evaluate coloured gemstones
Why aren’t coloured gemstones graded like diamonds? Comparing coloured stones and unsure what makes one better than another? You are not alone. Knowing how…
Article · 9 min
Why hue, tone and saturation matter in gemstones
Why colour matters so much in a coloured gemstone You have probably seen phrases like “medium-dark tone”, “vivid saturation” or “slightly violetish blue” in…
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