This route is really good early in the season. good stable snow cover is a must.
From the Argentier hut climb the right bank of the Amethyests glacier. cross to the gully coming down from the col superior Le Tour Noir. The route starts from here.
Enter the gully and at the first opportunity break out to the right onto the rocky crest. Climb this until a delicate traverse to the steep snow slope becomes necessary. Round the corner of the rock-face and into a narrowing of the gully which leads to the ridge. We came to a four meter vertical patch of rotten ice which was awkward. After this it is a straight forward snowslope to the narrow ridge. After the summit we descended the north ridge with some abseils to the col and then easily down to the glacier. Allow about five hours up from the hut and two back down.
A couple of ice screws and two axes are a must if the vertical ice patch is there. A few wires and quickdraws and a few slings should cover all bases.