Vertu, formerly Nokia's luxury brand of smartphone, has launched Constellation, one of the world's most expensive Android smartphones with prices starting at €4,900 ($6,690).

The company, which left Nokia last year, is hoping materials and craftsmanship will appeal to well heeled buyers. The device takes its cue from luxury watch makers, Vertu said, and was handmade in Hampshire, England.

The entire face of the 5.1-inch device is covered with a layer of sapphire crystal (pictured) weighing more than 100 carats, according to Vertu. So owners won't have to worry themselves about marks on the 4.3 inch 720p display — unless a diamond ring brushes it.

Its casing is made from polished titanium which, besides being lightweight and tougher than stainless steel, is expensive.

The Constellation's hardened face is counterbalanced by a backplate that's covered with a soft strip of calf leather, which says Vertu, comes from hides in the Alps. The backings come come in cappuccino, black, orange, mocha (pictured), and raspberry colours. 

Despite the high price tag for the Constellation range, it actually comes in at less than its predecessor, the Ti, which sold for €8,000 ($10,000) and was Vertu's first Android smartphone when it launched earlier this year.

Under Nokia, Vertu devices ran Symbian, but the Finnish handset maker sold the brand to private equity group EQT VI in late 2012 amid its massive restructure.