Month: December 2023

What’s in a name? Not much when it comes to conch pearls, the Caribbean’s contribution to mollusk-made gems. Gemologists treat…

After East African chrome tourmaline—a rare green tourmaline which, at its best, can double for fine tsavorite, even emerald—rubellite is…

When importer Richard Postrel buys pink sapphire from Burma tribesmen, they call it ruby—and don’t take kindly to contradiction. When…

Blessed is the corundum that contains rutile (titanium oxide). Not only does this mineral produce asterism—the star effect—in sapphires, it…

At its breathtaking best, tanzanite looks the spitting image of Kashmir sapphire—exhibiting the rich, royal velvety blue those stones are…

This sky-blue-color copper derivative, so important to the ancient Egyptians and Aztecs, has known better times. Perhaps the best times…