SET IN STONE

The world’s finest gemstones have been sought-after, fought over, and cherished for all human history. To this day, most gems are discovered in alluvial deposits—the sedimentary beds, banks, and coastlines of oceans, flooded basins, rivers, and streams that over time (a lot of time) carve out geologic formations and, occasionally, transport valuable treasures along their watery paths. In 1881, in the high altitude of the Himalayas’ Zanskar region, a natural tremor caused an otherwise unremarkable landslide that would reveal a pocket of uniquely blue corundum crystals. Discovered by a villager tending goats, the gemstones became highly prized for their velvety-blue hue, a characteristic partially attributed to the rutile needle–like inclusions, or “silk,” typical of Kashmir sapphires. The Maharaja of Kashmir purchased the mine, reserving the stones exclusively for Indian royalty.…