Tilasite
5 in the gallery
Tilasite is a calcium magnesium arsenate fluoride mineral. It typically forms in short prismatic or tabular crystals and can exhibit a subtle resinous to vitreous luster. Its color range includes pale to brownish tones, often presenting a discreet, earthy appearance that blends with surrounding gangue in its mineral deposits. The mineral commonly occurs in hydrothermal or pegmatitic environments where arsenate-bearing fluids crystallize with calcium, magnesium, fluoride and oxygen.
- Formula
- CaMg(AsO4)F
Where Tilasite is found
Top localities
- Wanni glacier - Scherbadung area2 specimens
- Binn Valley1 specimen
- Monte Cervandone1 specimen
About Tilasite
Notable specimens have been reported from Switzerland and Italy, among other arsenate-rich localities. Collectors value tilasite for its delicate crystal form and its rarity, which makes well-formed crystals a prized find in mineral collections. While not among the most visually flamboyant minerals, tilasite offers a quiet, geological intrigue for those documenting arsenate-bearing assemblages or seeking minerals tied to hydrothermal activity. Its compact habit and clean edges can make it a rewarding addition to an intellectually curious cabinet of minerals.