By Spectra Fine Jewelry, New York
The Collector's Encyclopedia
of Fine Jewelry
Expert guides on signed vintage jewelry, precious stones, and collecting intelligence — written by dealers who buy and sell at Christie's, Sotheby's, and Bonhams every season.
Brand Guides
Cartier, VCA, Bulgari, JAR, and 40+ signed houses — authentication, pricing, what to buy.
32+ brand guides
Stone Guides
Kashmir sapphire, Burma ruby, Colombian emerald, Paraíba tourmaline and more.
22+ stone guides
Era Guides
Art Deco, Retro, Edwardian, Victorian — how to identify, date, and value each period.
13+ era guides
Compare Guides
Side-by-side dealer comparisons — Kashmir vs Ceylon, Platinum vs White Gold, Signed vs Unsigned, and more.
14+ comparisons
Buying Guides
Estate jewelry, gemstone certifications, authentication checklists, and collecting strategy — written by working dealers.
2+ guides
Authenticate
Interactive checklists, hallmark guides, and photography guides for every major brand.
Free tool
Featured Guides
Shop Spectra's Curated Collection
Signed vintage jewelry, fancy color diamonds, and unheated sapphires — authenticated and available now.
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