Aiguilles Marbrées, Mountain summit at France-Italy border.

Aiguilles Marbrées is a 3535-meter peak positioned on the France-Italy border between Chamonix-Mont-Blanc and Courmayeur. Sharp granite peaks form its distinctive silhouette above the Glacier du Géant.

The north summit was first climbed on 17 August 1876 by Lionel Dècle, Henry Devouassoud and Édouard Cupelin via the north-east slope. The south summit followed on 22 July 1898, climbed by Adolfo Hess, Oscar Leitz and Laurent Croux from the Col du Géant. The first winter ascent, a traverse, was made on 21 January 1907 by G. Carugati, Mrs Carugati, Joseph Petigax and Laurent Petigax.

The name means "marbled needles", after the pale grey granite streaked with darker clefts. Quartz crystals grew in fissures in this granite 15 to 25 million years ago, and crystal hunters (cristalliers) worked these faces; a 2016 route on the north-west face is named the voie des Cristalliers after them.

Reaching the summit requires a cable car to Punta Helbronner station at 3462 meters, followed by crossing a glacier. Proper climbing equipment and mountaineering experience are needed.

The granite contains quartz crystal cavities formed 15 to 25 million years ago, when water infiltrated fissures opened by Alpine compression, dissolved silica and recrystallised it. A 2016 route on the north-west face is named voie des Cristalliers after the crystal hunters who worked these slopes.