Elbaite

Tourmaline from the Paprok mine has long been considered a classic, particularly known as "watermelon" tourmaline, characterized by a pink core and a green outer zone. However, in my opinion, a small find from several decades ago featuring gorgeous electric-blue terminations resting atop attractive blush-pink bases is even more beautiful. Unfortunately, only a handful of specimens were discovered, and among these, only the smaller crystals exhibited gemmy qualities.

Major tourmaline deposits worldwide are typically associated with igneous and metamorphic rocks. Although Brazilian pegmatites remain the primary source of gem-quality tourmaline, increasing discoveries in Afghanistan and Pakistan have begun to attract significant attention. The formation of tourmaline within igneous systems requires extensive magmatic differentiation, which concentrates boron (essential for forming tourmaline), trace elements (responsible for various colors), and water-rich (hydrothermal fluids). Interestingly, tourmaline composition can serve as an indicator of pegmatite evolution. In many localities, a chemical transition from Mg-rich schorl to Li-rich elbaite is observable from the outer wall zones to the core zones through ionic substitution.

Are blue-pink tourmalines related to green-pink "watermelon" tourmalines? Probably yes. It is well known that Mn³⁺ causes the pink coloration in tourmaline, whereas green coloration arises from the presence of Fe²⁺. Blue coloration results from intermetallic charge transfer between Fe²⁺ and Fe³⁺, likely influenced by natural radiation or increased oxidation. Similar to the greens, depth and intensity of the blue hue also directly correlate with the iron content.

I decided not to clean it, just keep it as when it came out of the mine. The matrix (lepidolite) will be bright purple after cleaning.

Elbite with lepidolite on albite, 3.8cm, Paprok, Kamdesh District, Nuristan, Afghanistan

Jingnan (Tom) Zhang Coll & Photo