A dazzling pink and grey crystal discovered in an Alpine crevasse and described as the "mineral Mona Lisa" has just been made a national cultural treasure – a historic first for a mineral.

The 11lb (5kg) crystal made of cognac fluorite on a smoked quartz base was found more than 3,000m (10,000ft) up Mont Blanc, Europe's highest mountain range.

Mr Peray found the rock on the Aiguille Verte (Green Needle), one of the most beautiful and perilous peaks in the Mont Blanc range – an Eldorado for crystal hunters from around the world.

Laurent is the first mineral to be classed a major cultural treasure for French heritage – an honour until now limited to cultural or man-made assets.