Did you know?
For a few years, San Diego County mined pink stones mostly for one customer on the other side of the world. Between 1902 and 1910 the mines shipped some 120 tons of gem rubellite to imperial China to feed the Empress Dowager Cixi's love of the color, and when she died and the Qing dynasty fell soon after, the market collapsed and the California boom went with it.
A single tourmaline crystal can change color along its length, red at one end and green at the other, the famous watermelon tourmaline. The colors record the chemistry of the fluid as the crystal grew: when the recipe shifted, so did the color, freezing a history of its own formation into one stone.
