Zambian or Colombian Emerald?Bonnot Paris · The Precious Stone Journal 2026 Zambian or Colombian Emerald? Two geologies, two greens, two gardens of inclusions. What truly distinguishes the two origins, why Colombian emeralds cost more — and why origin never tells the whole story of a stone. By François Deprez, founder · Comparison · 8 […]Bonnot Paris•September 22, 2026
Red spinel or ruby?Bonnot Paris · The Precious Stones Journal 2026 Red spinel or ruby? Two reds confused for six centuries. What truly sets them apart, what they cost per carat, what one undergoes and the other almost never does — and how to choose for a ring. By François Deprez, founder · Comparison · 8 min · […]Bonnot Paris•September 22, 2026
What Is My Birthstone?Bonnot Paris · The Precious Stones Journal 2026 What Is My Birthstone? The twelve months, from January to December: the stone, its origin, its colour, what it symbolises—and above all, the jewel that suits it, because not all of them can withstand being worn on the finger. By François Deprez, founder […]Bonnot Paris•September 22, 2026
The Price of TanzaniteBonnot Paris · The Precious Stone Journal 2026 The price of tanzanite What it costs per carat, what affects its price, why it is worth four times less than a blue sapphire of the same size — and the one consideration to know before turning it into a ring. By François Deprez, founder · Guide […]Bonnot Paris•September 22, 2026
How Much Does a Ruby Cost?Bonnot Paris · The Precious Stone Journal 2026 How much does a ruby cost? Figures from our own stock, stone by stone. Why the price per carat can fall as weight rises, how treatments affect value — and the alternative at a third of the price. By François Deprez, founder · Price guide · […]François Deprez•September 15, 2026
Ruby Wedding Anniversary: 35 Years of MarriageBonnot Paris · The Precious Stones Journal 2026 Ruby Wedding Anniversary Thirty-five years of marriage, and the stone of passion—not that of wisdom. What it represents, what it costs, where it comes from and how to choose yours. By François Deprez, founder · Anniversaries · 8 min · September 2026 Contents […]François Deprez•September 15, 2026
