Auction Gems Europe
Journal
Market news, auction results and gemmology guides. Sourced, dated and explained.
Unheated vs heated ruby and sapphire: price premium and report wording
Why no-heat rubies and sapphires cost more, what the evidence says about the premium, and how LMHC, GRS and Lotus word heat, residues, beryllium and glass.
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Gemstone colour grading by lab: why one report says vivid, another intense
How AIGS, GRS, Lotus, Bellerophon, GUILD, Gübelin, SSEF, GIA and AGL describe ruby and sapphire colour, why their terms don't line up, and how to compare reports.
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What 'royal blue' means on a sapphire report, lab by lab
How GRS, Gübelin, SSEF, Lotus, GIA, Bellerophon and others define royal blue sapphire, which accept heating, and how cornflower and peacock blue differ.
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What 'pigeon blood' means on a ruby report, lab by lab
GRS, Gübelin, SSEF, Lotus, GIA, Bellerophon, GUILD and others: how each lab defines pigeon blood ruby, which require no heat or fluorescence, and which accept Mozambique.
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How to verify a gemstone lab report: GIA, GRS, Gübelin, SSEF and more
How to check a gemstone certificate with each lab's online lookup, what a match does and does not prove, the red flags to watch for and what to do if in doubt.
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Gemstone auction checklist: 12 checks before you bid online
Twelve checks before bidding on a gemstone online: report type, laboratory, date and match, online verification, treatment and origin wording, reserve rules, total cost and deadlines.
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Catawiki fees for gemstones: what you really pay above the hammer price
The buyer protection fee, seller-set shipping, Swiss VAT, duty rules for loose stones and carrier charges, with two worked examples for a Swiss buyer at €1,000 and €5,000.
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Ceylon sapphire market 2026: shows, exports and what buyers should check
Sri Lanka's 2026 gem shows, export figures and reform promises, and why heating and origin reports still matter most to Ceylon sapphire buyers.
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Zambian emerald market 2026: what Gemfields' Kagem auctions reveal
A cautious higher-quality sale in May and a commercial sale in September at its best per-carat average in five auctions: the 2026 Kagem auctions, and what they mean for emerald buyers.
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Spinel buying guide: red, pink, cobalt blue and Mahenge stones
From the Black Prince's Ruby to Mahenge pink and cobalt blue: how to judge spinel, where it comes from, how labs detect heating and why demand has grown.
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Spessartite garnet buying guide: Mandarin colour, origins and value
How to judge spessartite garnet: what Mandarin and Fanta mean, where the best stones come from, what drives price and what to check before buying.
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Sapphire origin explained: Kashmir, Burma, Sri Lanka, Madagascar and beyond
How Kashmir, Burma, Sri Lanka and Madagascar sapphires differ, how labs determine origin, and what 2025-2026 auction results show about the origin premium.
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What makes a padparadscha sapphire? Colour, lab criteria and fading tests
How GIA, SSEF, Gübelin, GRS and AGL decide when a sapphire may be called padparadscha: colour, treatments, beryllium diffusion, fading tests and origins.
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