Precious stones · 1 May 2026
Red spinel: the royal fire the Earth kept untouched
Long mistaken for ruby in royal treasuries, red spinel now reveals its natural, vibrant and untreated flame.
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The Blog
Expertise & Know-how
Gemological guides, in-depth analyses and advice for jewellery professionals and discerning precious stone enthusiasts.
Pearls · 15 April 2026
Carved Vietnamese pearls: the new thrill in high jewellery
A saltwater pearl sculpted, reimplanted, then illuminated by a new layer of nacre: an organic rarity for the most distinctive jewellery creations.
Read article →Pearls · 15 March 2026
Akoya Pearls: the complete guide for jewellers
Lustre, size, orient, quality — everything you need to know to select, present and add value to Akoya pearls in your jewellery business.
Read article →Precious stones · 1 March 2026
Treated vs untreated sapphire: what it really changes
Heating is the norm in the sapphire trade. But what exactly does 'untreated' mean? And why does this criterion have such a profound impact on a stone's value?
Read article →Precious stones · 15 February 2026
Padparadscha spinel: the rarest gemstone you haven't discovered yet
Between pink and orange, the padparadscha colour is among the most sought-after in the world. Origin, characteristics, value, jewellery uses — the complete guide.
Read article →Gemology · 1 February 2026
Gemological certification: which laboratory to choose for your stones?
The world's leading gemological laboratories are not all equal. Their criteria, processes and impact on stone value differ. A comparative guide.
Read article →Expertise · 15 January 2026
Investment precious stones: what professionals know
Untreated sapphires, spinels, Paraíba tourmalines — certain gemstones represent remarkable stores of value. What jewellers and collectors need to know.
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